1,484 research outputs found
Simultaneous localization and odometry self calibration for mobile robot
This paper presents both the theory and the experimental results of a method allowing simultaneous robot localization and odometry error estimation (both systematic and non-systematic) during the navigation. The estimation of the systematic components is carried out through an augmented Kalman filter, which estimates a state containing the robot configuration and the parameters characterizing the systematic component of the odometry error. It uses encoder readings as inputs and the readings from a laser range finder as observations. In this first filter, the non-systematic error is defined as constant and it is overestimated. Then, the estimation of the real non-systematic component is carried out through another Kalman filter, where the observations are obtained by two subsequent robot configurations provided by the previous augmented Kalman filter. There, the systematic parameters in the model are regularly updated with the values estimated by the first filter. The approach is theoretically developed for both the synchronous and the differential drive. A first validation is performed through very accurate simulations where both the drive systems are considered. Then, a series of experiments are carried out in an indoor environment by using a mobile platform with a differential driv
INDAGINE SULLA PRESENZA DEL VIRUS DELL’EPATITE E NEL SUINO IN ALLEVAMENTI TOSCANI
L’infezione da Hepatitis E Virus (HEV) nei suini e nell’uomo è stata segnalata in diversi Paesi. Nei suini, il virus causa infezioni asintomatiche, mentre nell’uomo è responsabile di epidemie di epatite nei Paesi in via di sviluppo e di casi sporadici in quelli sviluppati. Indagini sierologiche condotte su persone a stretto contatto con suini hanno evidenziato una sieroprevalenza maggiore rispetto alla popolazione di controllo. Studi filogenetici hanno riscontrato un alto grado di omologia tra stipiti di origine umana e suina isolati nella medesima area geografica. È stato accertato il passaggio dell’infezione dal suino all’uomo attraverso l’ingestione di carni infette. Allo stato attuale delle conoscenze si pensa pertanto che il suino possa fungere da fonte di contagio per l’uomo. In Italia, HEV è stato isolato per la prima volta dall’uomo nel 1999, mentre l’infezione nel suino è stata segnalata solo nel 2006. In questa indagine, mediante analisi di campioni fecali con la tecnica Nested RT-PCR, è stata ricercata la presenza di HEV in suini di allevamenti toscani. Nel 43% degli allevamenti esaminati è stata evidenziata la presenza del virus. Il maggior numero di campioni positivi è stato riscontato nella classe di età compresa fra 3 e 5 mesi. Alcuni dei nostri amplificati virali sono stati sequenziati e messi a confronto con quelli disponibili in banche dati. L’analisi filogenetica ha rilevato una forte omologia con gli isolati umani e suini di origine europea
A comparison of line extraction algorithms using 2D range data for indoor mobile robotics
This paper presents an experimental evaluation of different line extraction algorithms applied to 2D laser scans for indoor environments. Six popular algorithms in mobile robotics and computer vision are selected and tested. Real scan data collected from two office environments by using different platforms are used in the experiments in order to evaluate the algorithms. Several comparison criteria are proposed and discussed to highlight the advantages and drawbacks of each algorithm, including speed, complexity, correctness and precision. The results of the algorithms are compared with ground truth using standard statistical methods. An extended case study is performed to further evaluate the algorithms in a SLAM applicatio
Reputation-based composition of social web services
Social Web Services (SWSs) constitute a novel paradigm of service-oriented computing, where Web services, just like humans, sign up in social networks that guarantee, e.g., better service discovery for users and faster replacement in case of service failures. In past work, composition of SWSs was mainly supported by specialised social networks of competitor services and cooperating ones. In this work, we continue this line of research, by proposing a novel SWSs composition procedure driven by the SWSs reputation. Making use of a well-known formal language and associated tools, we specify the composition steps and we prove that such reputation-driven approach assures better results in terms of the overall quality of service of the compositions, with respect to randomly selecting SWSs. © 2014 IEEE
Case report: p.Glu134del SOD1 mutation in two apparently unrelated ALS patients with mirrored phenotype
With upcoming personalized approaches based on genetics, it is important to report new mutations in amyotrophic lateral sclerosis (ALS) genes in order to understand their pathogenicity and possible patient responses to specific therapies. SOD1 mutations are the second most frequent genetic cause of ALS in European populations. Here, we describe two seemingly unrelated Italian patients with ALS carrying the same SOD1 heterozygous c.400_402 deletion (p.Glu134del). Both patients had spinal onset in their lower limbs, progressive muscular weakness with respiratory involvement, and sparing bulbar function. In addition to the clinical picture, we discuss the possible pathogenic role of this unfamiliar SOD1 mutation
Novel protein-truncating variant in the APOB gene may protect from coronary artery disease and adverse cardiovascular events
Background and aims: Genetic testing is still rarely used for the diagnosis of dyslipidemia, even though gene variants determining plasma lipids levels are not uncommon.Methods: Starting from a a pilot-analysis of targeted Next Generation Sequencing (NGS) of 5 genes related to familial hypercholesterolemia (LDLR, APOB, PCSK9, HMGCR, APOE) within a cardiovascular cohort in subjects with extreme plasma concentrations of low-density lipoprotein (LDL) cholesterol, we discovered and characterized a novel point mutation in the APOB gene, which was associated with very low levels of apolipoprotein B (ApoB) and LDL cholesterol.Results: APOB c.6943 G > T induces a premature stop codon at the level of exon 26 in the APOB gene and generates a protein which has the 51% of the mass of the wild type ApoB-10 0 (ApoB-51), with a trun-cation at the level of residue 2315. The premature stop codon occurs after the one needed for the synthesis of ApoB-4 8, allowing chylomicron production at intestinal level and thus avoiding potential nutritional impairments. The heterozygous carrier of APOB c.6943G > T, despite a very high-risk profile encompassing all the traditional risk factors except for dyslipidemia, had normal coronary arteries by angiography and did not report any major adverse cardiovascular event during a 20-years follow-up, thereby obtaining advantage from the gene variant as regards protection against atherosclerosis, apparently without any metabolic retaliation.Conclusions: Our data support the use of targeted NGS in well-characterized clinical settings, as well as they indicate that.a partial block of ApoB production may be well tolerated and improve cardiovascular outcomes. (C) 2022 The Authors. Published by Elsevier B.V
Sustainable Valorisation and Efficient Downstream Processing of Giant Reed by High-Pressure Carbon Dioxide Pretreatment
This work investigated the catalytic high-pressure CO2 pretreatment of giant reed. CO2 is a renewable resource; its use does not generate chemical wastes and it can be easily removed and recycled. The effect of the addition of low concentrations of FeCl3 (0.16 wt%) and PEG 400 (1.0 wt%) on the hemicellulose hydrolysis to xylose and xylo-oligosaccharides (XOS) is reported for the first time. Under the optimised pretreatment conditions, the xylan conversion of 82 mol% and xylose and XOS yields of 43 and 20 mol% were achieved, respectively. The solid residues obtained from different pretreatments were used as the substrate for the enzymatic hydrolysis to give glucose. The total glucose yield achieved under the optimised two-step process was 67.8 mol% with respect to the glucan units in the biomass. The results demonstrated that PEG-assisted FeCl3-catalysed scCO(2) pretreatment can produce xylose- or XOS-rich hydrolysates and improve the enzymatic hydrolysis of biomass
An Iterative Refining Approach to Design the Control of Wave Energy Converters with Numerical Modeling and Scaled HIL Testing
The aim of this work is to show that a significant increase of the e_ciency of aWave Energy Converter (WEC) can be achieved already at an early design stage, through the choice of a turbine and control regulation, by means of an accurate Wave-to-Wire (W2W) modeling that couples the hydrodynamic response calibrated in a wave flume to a Hardware-In-the-Loop (HIL) test bench with sizes and rates not matching those of the system under development. Information on this procedure is relevant to save time, because the acquisition, the installation, and the setup of a test rig are not quick and easy. Moreover, power electronics and electric machines to emulate turbines and electric generators matching the real systems are not low-cost equipment. The use of HIL is important in the development of WECs also because it allows the carrying out of tests in a controlled environment, and this is again time- and money-saving if compared to tests done on a real system installed at the sea. Furthermore, W2W modeling can be applied to several Power Take-O_ (PTO) configurations to experiment di_erent control strategies. The method here proposed, concerning a specific HIL for testing power electronics and control laws for a specific WECs, may have a more general validity.This work was supported by MARINET, a European Community—Research Infrastructure Action
under the FP7 “Capacities” Specific Programme, grant agreement n. 262552
Design and validation of a self-administered questionnaire to assess knowledge, attitudes and behaviours about Zika virus infection among general population in Italy
Background Zika (ZIKV), a flavivirus firstly identified in rhesus monkeys in Zika Forest of Uganda, in 1947, is an emerging virus transmitted mainly by mosquitoes bites. Due to ZIKV adaptation to humans, that can maintain a mosquito-human-mosquito transmission cycle, it is essential to know the attitudes, knowledge and behaviours of general population regarding ZIKV prevention. Our main study aims were to develop and validate a questionnaire administered to the general population, in order to assess attitudes, knowledge and behaviours around prevention and control of Zika infection. Methods A questionnaire was developed based on a comprehensive review of the extant literature, pre-existing questionnaires and experts focus groups. Results The final, validation version of the questionnaire comprised 8 items, with good psychometric properties (Cronbach’s alpha of 0.81). Overall test/re-test concordance was 0.86, ranging from 0.76 to 0.94 according to each item. Conclusion In conclusion, the questionnaire seems to be an appropriate and useful tool to detect cognitive gaps concerning behaviours responsible for possible transmissions of the disease, even in a non-endemic country such as Italy. Future analysis will explore the factorial structure of the questionnaire as well as knowledge, beliefs and attitudes concerning ZIKV among Italian general population
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