rare left ventricular metastasis from uveal melanoma

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Earth-Moon multiPurpose orbiting infrastructure

Nowadays interest on large structures, ISS like, to serve for a long time as orbiting outposts place in strategic, possibly long-term stable locations is increasing. They can serve as a support for far target roboticmanned missions, for planetary tele-operated robotic surface activities, as scientific labs for sample return missions in preserved environment avoiding contamination, for astronauts training, for refueling and maintenance of deep space vessels. Whatever the exploitation is such large structure would undergo numerous docking\undocking activities with a time dependent matrix of inertia; it should require a large lifetime along with orbital stability would be also needed and, being the structure extended, a strongly coupled attitudeorbital dynamics is expected. Lagrangian points are an evident appealing location for such an infrastructure offering stable trajectories as well as well suited relative positioning with respect to the Sun and the other planets to be considered in the 3 body system. The investigation of the relative dynamics on non-keplerian orbits is the topic of the paper: a case study is presented for the EMPIRE (Earth-Moon multiPurpose orbIting infRastructurE) scenario: EMPIRE is a long-term multipurpose extended structure placed on Halo around the L1 in the Earth-Moon system, many different space complex and articulated missions may benefit of. The rendez-vous and approach phases between EMPIRE and any attachable module are formalized for the CR3BP together with the guidance profile to gain the nominal final state vector. Effects of perturbations on the EMPIRE extended configuration in terms of attitudeCoM coupled effects are also discussed

SatLeash - Parabolic flight validation of tethered-tugs dynamics and control for reliable space transportation applications

The SatLeash experiment investigates the dynamics and control of tow-tethers, for space transportation. Understanding tethered towing objects in space is becoming an active research field for its range of applications. Many missions, such as Active Debris Removal, LEO satellites disposal, low-to-high energy orbit transfer and even asteroids retrieval could employ this technology. Space tugs, made of a passive orbiting target interconnected through a flexible link to an active chaser the thrusters of which excite the stack dynamics, open new challenges for guidance and control design. A wave-based control, using tension feedback, is selected as effective method to stabilize the system during tensioning and release phases. The team exploits a multibody dynamics simulator developed at PoliMi-DAER-to describe tethered-satellite-systems dynamics and synthetize their control. This is considered of primary importance to design future missions. The experiment, selected to fly in microgravity conditions by the ESA FlyYourThesis! 2016 programme, focuses on validating the adopted models and verifying the implemented control law. A reduced-scale tethered floating test bed, equipped with a stereovision system to reconstruct its 3D trajectory, has been developed for the parabolic flight campaign. Different tether stiffness have been tested as well as control schemes to verify their effectiveness in reducing bouncing-back effects. Developed models and control laws, together with numerical and experimental simulation results are presented in the paper

Rare left ventricular metastasis from uveal melanoma

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Parabolic Flight Experiment to Validate Tethered-Tugs Dynamics and Control for Reliable Space Transportation Applications

The Fly Your Thesis! programme of the European Space Agency's Education Office offers university students the opportunity to conduct their scientific experiments in microgravity conditions, during a parabolic flight campaign. In this framework, the PoliTethers team, from Politecnico di Milano, Department of Aerospace Science and Technologies, was selected to fly an experiment on-board Novespace's Zero-G aircraft, the flight campaign being scheduled for October 2016. The SatLeash experiment is going to investigate the dynamics and control of tow-tethers, for space transportation: tethered towing objects in space is becoming an appealing concept for many missions, such as Active Debris Removal, LEO satellites disposal, low-to-high energy orbit transfer and even asteroids retrieval. Space tugs, made of a passive orbiting target interconnected through a flexible link to an active chaser the thrusters of which excite the stack dynamics, open new challenges for guidance and control design. The chaser is required to robustly and reliably perform operations, while damping dangerous vibrations of flexible elements and connections, avoiding instability, collisions and tether entanglement. One of the most common critical modes that may arise during towing operations is the bounce-back effects: whenever thrust is shut down, the tether slackens and the residual tension accelerates the two objects towards each other, increasing the collision risk; the control recovery is then difficult and not always possible. The tether may entangle on the target or the chaser itself and, hence, break. Control methods based on feedforward shaping of the pulling thrust proved to be effective in simulation, stabilizing the system by cutting off the tethered-system's first modes frequencies, significantly reducing the bounce back. Validated simulation tools describing tethered-tugs dynamics, and their stabilization via control laws, are considered of primary importance to design future missions. To this end, the team exploits a multibody dynamics simulator - developed at PoliMi-DAER - to describe tethered-satellite-systems dynamics and synthetize their control. The in-flight experiment focuses on validating the adopted models and verifying the implemented control laws. A reduced-scale tethered floating testbed is going to fly equipped with a stereovision system to reconstruct its 3D trajectory. Different tether stiffness will be tested as well as differently-shaped open-loop thrust profiles to verify their effectiveness in reducing bouncing-back effects. Developed models and control laws, together with numerical simulation results will be presented; the experiment design and integration will also be described and ground tests' results will be summarised

Artificial intelligence and anesthesia: a narrative review

Background and objective: The aim of this narrative review is to analyze whether or not artificial intelligence (AI) and its subsets are implemented in current clinical anesthetic practice, and to describe the current state of the research in the field. AI is a general term which refers to all the techniques that enable computers to mimic human intelligence. AI is based on algorithms that gives machines the ability to reason and perform functions such as problem-solving, object and word recognition, inference of world states, and decision-making. It includes machine learning (ML) and deep learning (DL). Methods: We performed a narrative review of the literature on Scopus, PubMed and Cochrane databases. The research string comprised various combinations of "artificial intelligence", "machine learning", "anesthesia", "anesthesiology". The databases were searched independently by two authors. A third reviewer would mediate any disagreement the results of the two screeners. Key content and findings: The application of AI has shown excellent results in both anesthesia and in operating room (OR) management. In each phase of the perioperative process, pre-, intra- and postoperative ones, it is able to perform different and specific tasks, using various techniques. Conclusions: Thanks to the use of these new technologies, even anesthesia, as it is happening for other disciplines, is going through a real revolution, called Anesthesia 4.0. However, AI is not free from limitations and open issues. Unfortunately, the models created, provided they have excellent performance, have not yet entered daily practice. Clinical impact analyzes and external validations are needed before this happens. Therefore, qualitative research will be needed to better understand the ethical, cultural, and societal implications of integrating AI into clinical workflows