Modelling, Simulation and Testing of a Reconfigurable Cable-Based Parallel Manipulator as Motion Aiding System

This paper presents results on the modelling, simulation and experimental tests of a cable-based parallel manipulator to be used as an aiding or guiding system for people with motion disabilities. There is a high level of motivation for people with a motion disability or the elderly to perform basic daily-living activities independently. Therefore, it is of great interest to design and implement safe and reliable motion assisting and guiding devices that are able to help end-users. In general, a robot for a medical application should be able to interact with a patient in safety conditions, i.e. it must not damage people or surroundings; it must be designed to guarantee high accuracy and low acceleration during the operation. Furthermore, it should not be too bulky and it should exert limited wrenches after close interaction with people. It can be advisable to have a portable system which can be easily brought into and assembled in a hospital or a domestic environment. Cable-based robotic structures can fulfil those requirements because of their main characteristics that make them light and intrinsically safe. In this paper, a reconfigurable four-cable-based parallel manipulator has been proposed as a motion assisting and guiding device to help people to accomplish a number of tasks, such as an aiding or guiding system to move the upper and lower limbs or the whole body. Modelling and simulation are presented in the ADAMS environment. Moreover, experimental tests are reported as based on an available laboratory prototype

Stellar populations in the dwarf spheroidal galaxy Leo I

We present a detailed study of the color magnitude diagram (CMD) of the dwarf spheroidal galaxy Leo I, based on archival Hubble Space Telescope data. Our photometric analysis, confirming previous results on the brighter portion of the CMD, allow us to obtain an accurate sampling of the stellar populations also at the faint magnitudes corresponding to the Main Sequence. By adopting a homogeneous and consistent theoretical scenario for both hydrogen and central helium-burning evolutionary phases, the various features observed in the CMD are interpreted and reliable estimations for both the distance modulus and the age(s) for the main stellar components of Leo I are derived. More in details, from the upper luminosity of the Red Giant Branch and the lower luminosity of the Subgiant Branch we simultaneously constrain the galaxy distance and the age of the oldest stellar population in Leo I. In this way we obtain a distance modulus (m-M)_V=22.00$\pm$0.15 mag and an age of 10--15 Gyr or 9--13 Gyr, adopting a metallicity Z=0.0001 and 0.0004, respectively. The reliability of this distance modulus has been tested by comparing the observed distribution of the Leo I anomalous Cepheids in the period-magnitude diagram with the predicted boundaries of the instability strip, as given by convective pulsating models.Comment: 19 pages, 3 tables, 14 figures To be published in A

Integrated process of images and acceleration measurements for damage detection

The use of mobile robots and UAV to catch unthinkable images together with on-site global automated acceleration measurements easy achievable by wireless sensors, able of remote data transfer, have strongly enhanced the capability of defect and damage evaluation in bridges. A sequential procedure is, here, proposed for damage monitoring and bridge condition assessment based on both: digital image processing for survey and defect evaluation and structural identification based on acceleration measurements. A steel bridge has been simultaneously inspected by UAV to acquire images using visible light, or infrared radiation, and monitored through a wireless sensor network (WSN) measuring structural vibrations. First, image processing has been used to construct a geometrical model and to quantify corrosion extension. Then, the consistent structural model has been updated based on the modal quantities identified using the acceleration measurements acquired by the deployed WSN. © 2017 The Authors. Published by Elsevier Ltd

First data on genetic diversity of the small pearl oyster Pinctada Radiata (Leach, 1814) in Mediterranean populations by means of the mitochondrial COX1 marker

This study gives a first molecular insight into the genetic structure of Pinctada radiata by analysing a mitochondrial DNA marker in four South -Central Mediterranean populations of this lessepsian bivalve. Specimens were collected from four central Mediterranean locations. Six polymorphic sites were found, defining seven haplotypes. Haplotype and nucleotide diversity values were low to moderate. The low levels of within -population genetic diversity detected in the present study are consistent with a scenario of founder effect, as expected for an invasive species. The shallow genetic structuring among the sampled populations may result from two factors – long larval duration which promotes the homogenization of the genetic pool through an effective gene flow or the current populations may not have had enough time to differentiate.peer-reviewe

Defective Function of the Fas Apoptotic Pathway in Type 1 Diabetes Mellitus Correlates with Age at Onset

The Fas death receptor triggers lymphocyte apoptosis through an extrinsic and an intrinsic pathway involving caspase-8 and -9 respectively. Inherited defects of Fas function are displayed by a proportion of patients with Type 1 diabetes mellitus (T1DM) especially those with a second autoimmunity (T1DM-p). This study assesses activation of both pathways in Fas-resistant (FasR) patients to localize the defect. 21/28 (75%) T1DM-p, 14/50 (38%) T1DM, and 7/150 (5%) controls were FasR. Analysis of the 35 FasR patients and 20 Fas-sensitive (FasS) controls showed that caspase-9 activity was lower in T1DM-p and T1DM than in controls, whereas caspase-8 activity was lower in T1DM-p than in T1DM and the controls. Single patient analysis showed that 16/35 patients displayed defective activity of one (FasR1), whereas 19 displayed normal activity of both caspases (FasR2) Ages at onset of diabetes mellitus in T1DM and the second autoimmune disease in T1DM-p were lower in FasR than in FasS patients. All FasR1 patients developed diabetes mellitus before the age of 9 years, whereas a later onset was displayed by 26% FasR2 and 53% FasS patients. These data show that defective Fas function may involve both the extrinsic and intrinsic pathway in T1DM and severity correlates with the precocity of the autoimmune attack and its tissue polyreactivity

Chemotherapy effects on brain glucose metabolism at rest

Background: A growing number of studies reports that chemotherapy may impair brain functions inducing cognitive changes which can persist in a subset of cancer survivors. Aims: To investigate the neural basis of the chemotherapy-induced neurobehavioral changes by means of metabolic imaging and voxel-based statistical parametric mapping analyses. Methods: We studied the resting brain [18]FDG-PET/CT images of 43 adult cancer patients with solid (n=12, 28%) or hematologic malignancies (n=31, 72%); 12 patients were studied prior to chemotherapy (No chemotherapy) while treated patients were divided into two matched subgroups: Early High (6 chemotherapy cycles, n=10), and Late Low (>9 months after chemotherapy, <6 chemotherapy cycles, n=21). Findings: Compared to No chemotherapy, the Early High subgroup showed a significant bilateral (p<0.05) lower regional cerebral metabolic rate of glucose metabolism in both the prefrontal cortices and white matter, cerebellum, posterior medial cortices and limbic regions. A similar pattern emerged in the Early High versus Low Late comparison, while no significant result was obtained in the Low Late versus No chemotherapy comparison. The number of cycles and the post-chemotherapy time were negatively and positively correlated, respectively, with a set of these same brain regions. Interpretation: The present study shows that chemotherapy induces significant transient changes in the glucose metabolism of multiple cerebral cortical and white matter regions with a prevailing involvement of the prefrontal cortex. The severity of these changes are significantly related with the number of chemotherapy cycles and a subset of brain regions seems to present longer lasting, but more subtle, metabolic changes