Sull'emissione filatelica celebrativa del MMD anniversario del giuramento della plebe al Monte Sacro e dell'istituzione del tribuno della plebe

Sommario: 1. Il Tribunato della plebe nell’età repubblicana; 2. Da Augusto al XVII secolo; 3. Dal XVIII secolo alla Rivoluzione russa; 4. Dall’Ombudsman al Defensor del pueblo

Analisi cartografica e GPS di punti fiduciali

Scopo di questo lavoro \ue8 l'analisi cartografica di punti fiduciali (P.F.), attraverso la comparazione delle coordinate di un dataset di sessanta vertici presenti nella citt\ue0 di Palermo. Come supporto cartografico di riferimento \ue8 stato preso la carta ufficiale del Comune di Palermo, che \ue8 in formato digitale ed \ue8 stata recentemente realizzata con metodo aerofotogrammetrico (2007). Le coordinate dei punti fiduciali sono state confrontate con differenti supporti cartografici e web: mappe catastali georiferite (nel sistema nazionale Gauss-Boaga), mappe derivanti dagli applicativi web Google Earth e fiduciali.it. Oltre ai confronti con i supporti cartografici dei P.F., \ue8 stata effettuata una vasta campagna di rilievi GPS/GNNS in modalita NRTK con stazionamenti fuoricentro, legati alla particolare natura dei punti rilevati (in maggioranza spigoli di fabbricati); questo metodo, ampiamente utilizzato in letteratura, ha richiesto un lavoro molto oneroso poich\ue9 \ue8 stato necessario rilevare direttamente i P.F. L'analisi sviluppata dimostra l'adeguatezza del rilievo NRTK alla determinazione delle coordinate dei P.F., mentre i risultati provenienti dagli applicativi Google Earth e fiduciali.it sono in forte discontinuit\ue0 rispetto alla Cartografia Tecnica Comunale

On the motion/stiffness decoupling property of articulated soft robots with application to model-free torque iterative learning control

This paper tackles the problem of controlling articulated soft robots (ASRs), i.e., robots with either fixed or variable elasticity lumped at the joints. Classic control schemes rely on high-authority feedback actions, which have the drawback of altering the desired robot softness. The problem of accurate control of ASRs, without altering their inherent stiffness, is particularly challenging because of their complex and hard-to-model nonlinear dynamics. Leveraging a learned anticipatory action, Iterative Learning Control (ILC) strategies do not suffer from these issues. Recently, ILC was adopted to perform position control of ASRs. However, the limitation of position-based ILC in controlling variable stiffness robots is that whenever the robot stiffness profile is changed, a different input action has to be learned. Our first contribution is to identify a wide class of ASRs, whose motion and stiffness adjusting dynamics can be proved to be decoupled. This class is described by two properties that we define: strong elastic coupling - relative to motors and links of the system, and their connections - and homogeneity - relative to the characteristics of the motors. Furthermore, we design a torque-based ILC scheme that, starting from a rough estimation of the system parameters, refines the torque needed for the joint positions tracking. The resulting control scheme requires minimum knowledge of the system. Experiments on variable stiffness robots prove that the method effectively generalizes the iterative procedure w.r.t. the desired stiffness profile and allows good tracking performance. Finally, potential restrictions of the method, e.g., caused by friction phenomena, are discussed

Decentralized Trajectory Tracking Control for Soft Robots Interacting With the Environment

Despite the classic nature of the problem, trajectory tracking for soft robots, i.e., robots with compliant elements deliberately introduced in their design, still presents several challenges. One of these is to design controllers which can obtain sufficiently high performance while preserving the physical characteristics intrinsic to soft robots. Indeed, classic control schemes using high-gain feedback actions fundamentally alter the natural compliance of soft robots effectively stiffening them, thus de facto defeating their main design purpose. As an alternative approach, we consider here using a low-gain feedback, while exploiting feedforward components. In order to cope with the complexity and uncertainty of the dynamics, we adopt a decentralized, iteratively learned feedforward action, combined with a locally optimal feedback control. The relative authority of the feedback and feedforward control actions adapts with the degree of uncertainty of the learned component. The effectiveness of the method is experimentally verified on several robotic structures and working conditions, including unexpected interactions with the environment, where preservation of softness is critical for safety and robustness

Locally advanced leiomyosarcoma of the spleen. A case report and review of the literature

<p>Abstract</p> <p>Background</p> <p>Leiomyosarcomas are rare tumours, predominantly localized in the stomach, small intestine and retroperitoneum. Only one case of primary leiomyosarcoma of the spleen is described in human beings in literature.</p> <p>Case presentation</p> <p>We report a case of locally advanced primary leiomyosarcoma of the spleen in a 54 year-old woman, diagnosed only after splenectomy, performed with the suspicion of splenic haematoma.</p> <p>Conclusion</p> <p>Due to the lack of cases, no specific chemotherapy regimen has been tested to provide a longer survival.</p

Longitudinal association of 25-Hydroxyvitamin D with adipokines and markers of glucose metabolism among Brazilian pregnant women

This study aimed to evaluate the longitudinal association of vitamin D status with glycaemia, insulin, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), adiponectin and leptin. A prospective cohort with 181 healthy, pregnant Brazilian women was followed at the 5th–13th, 20th–26th, and 30th–36th gestational weeks. In this cohort, 25(OH)D plasma concentrations were analysed using liq¬uid chromatography-tandem mass spectrometry. Vitamin D status was categorized as sufficient or insufficient using the Endocrine Society Practice Guidelines (ES) (≥75/<75 nmol/L) and the Institute of Medicine (IOM) (≥50/<50 nmol/L) thresholds. Linear mixed-effect regression models were employed to evaluate the association between vitamin D status and each outcome, considering the interaction terms between vitamin D status and gestational age (P<0.1). At baseline, 70.7% of pregnant women had 25(OH)D levels <75 nmol/L and 16% had levels <50 nmol/L. Women with sufficient vitamin D status at baseline, using both the ES and IOM thresholds, presented lower glycaemia than those with insufficient 25(OH)D. Pregnant women with 25(OH)D concentrations <75 nmol/L showed lower insulin (β=-0.12; 95% CI -0.251, 0.009; P=0.069) and adiponectin (β=-0.070; 95% CI -0.150, 0.010; P=0.085) concentrations throughout pregnancy than those with 25(OH)D levels ≥75 nmol/L. Pregnant women with 25(OH)D <50 nmol/L at baseline presented significantly higher leptin concentrations than those with 25(OH)D levels ≥50 nmol/L (β=-0.253, 95% CI: -0.044; 0.550, P=0.095). The baseline status of vitamin D influences the biomarkers involved in glucose metabolism. Vitamin D sufficient women at baseline had higher increases of insulin and adiponectin changes throughout gestation than those who were insufficient