2,876 research outputs found
Fondamenti di biomeccanica. Equilibrio, movimento e deformazione
No full textFONDAMENTI DI BIOMECCANICA, a cura di Angelo Cappello e Lorenzo Chiari, con la collaborazione di Luca Cristofolini, è considerato un testo di riferimento a livello internazionale e si rivolge a platee di lettori molto diverse, con una cifra stilistica deliberatamente inclusiva. Gli Autori della terza edizione (Nihat Özkaya, Margareta Nordin, David Goldsheyder e Dawn Leger) hanno abbinato il necessario formalismo matematico con ampie sezioni descrittive, cercando di fare avvicinare ciascun lettore, indipendentemente dal suo retroterra culturale, al cuore dei costrutti fondamentali relativi a equilibrio, movimento e deformazione. Un corpus notevole di esempi ed esercizi risolti è di grande utilità pratica. La crescente domanda di competenze biomeccaniche in ambiti professionali diversi rende il testo adatto ai corsi di laurea e laurea magistrale di Ingegneria dell’Informazione o Industriale, Ingegneria Biomedica, Scienze delle Attività Motorie e Sportive, Scienze e Tecniche delle Attività Motorie Preventive e Adattate, Scienze e Tecniche dello Sport, Scienze delle Professioni Sanitarie della Riabilitazione e delle Professioni Sanitarie Tecniche, Medicina e Chirurgia
The Classics of the First Lorenzo de' Medici. For a New Critical Reading of Corinth
No full textopenIl presente lavoro si propone di rileggere una delle prime opere di Lorenzo de’ Medici, "Corinto", attraverso temi letterari che lo caratterizzano, tenendo presente i modelli latini, greci e italiani ai quali l’autore attinge e confrontandone altri, pertinenti ai temi analizzati. Dopo una rapida introduzione sul contesto storico in cui il poemetto si inserisce, esso viene presentato per quanto concerne il contenuto e la storia redazionale, approfondita nell’Appendice, dove si presentano inoltre i testi di riferimento. Segue dunque la nuova lettura critica. La riflessione sul concetto di classico e su Lorenzo quale autore e personaggio del poemetto conclude l’analisi.The present work aims to re-read one of Lorenzo de’ Medici’s first works, "Corinto", through the literary themes which characterize it, keeping in mind the Latin, Greek and Italian models on which the author draws and comparing others, pertinent to the themes analyzed. After a quick introduction to the historical context in which the poem fits, it is presented in terms of content and editorial history, detailed in the Appendix, where the reference texts are also presented. Thus follows the new critical reading. The reflection on the concept of classic and on Lorenzo as author and character of the poem concludes the analysis
A portable system for in-situ calibration of force platforms: Theoretical validation
No full textThe periodic calibration of measurement devices, such as force platforms (FPs), guarantees and optimizes the quality of the acquired data.
In this study, the theoretical validation of a portable system for the in-situ calibration of six-component FPs is presented. A least-squares
algorithm, that estimates the FP re-calibration matrix, was designed and tested using a simulation approach. The algorithm is the core of a
portable system, described in a separate paper, and represents a refinement of an algorithm previously presented by Cappello et al. [Cappello
A, Lenzi D, Chiari L. Periodical in-situ re-calibration of force platforms: a new method for the robust estimation of the calibration matrix. Med
Biol Eng Comput 2004;42:350–5]. The new algorithm assumes that the calibration inputs are known, 3-D, time-varying loads, applied to the
FP at known coordinates, and not constrained in their direction of application. Simulation results confirmed the a priori identifiability of the
re-calibration matrix and some of the algorithm features were optimized in the perspective of an actual building of the system.With the aid of
simple sinusoidal loads, applied in at least five different points, we proved that the algorithm can ensure errors less than 0.2 N and 0.4 Nm
when calculating force and moment components of an applied load
A portable system for in-situ re-calibration of force platforms: experimental validation
No full textA system for the in-situ re-calibration of six-component force platforms is presented. The system consists of a device, a data-acquisition procedure and an algorithm. The device, simple and lightweight, is composed of a high-precision, 3-D load cell, loaded through a triangular stage, and precisely positioned on the force platform under re-calibration by means of a template. The data-acquisition procedure lasts about 1h and requires up to 13 measurements consisting of manual positioning the load cell on the force platform, and then having the operator exerting loads on both load cell and force platform by his/her body movement. As a result, the procedure makes use of loads in the same range of posture and gait tests. The algorithm estimates the local or global six-by-six re-calibration matrix of the force platform through a least-squares optimization, and is presented in detail in a separate paper [Cedraro A, Cappello A, Chiari L., A portable system for in-situ re-calibration of force platforms: Theoretical validation. Gait Posture 2008;28:488-94]. The system was validated on four commercial force platforms (Amti OR6, Bertec 4060-08, Bertec 4080-10, and Kistler 9286A). The average accuracy in the measurement of the center of pressure were 2.3+/-1.4mm, 2.6+/-1.5mm, 11.8+/-4.3mm, 14.0+/-2.5mm before re-calibration, 1.1+/-0.6mm, 1.8+/-1.1mm, 1.0+/-0.6mm, 3.2+/-1.1mm after global re-calibration, and 0.7+/-0.4mm, 0.8+/-0.5mm, 0.5+/-0.3mm, 2.0+/-1.2mm after local re-calibration (results presented in random order). The force platform re-calibration influenced the value, sign, and timing of net joint moments, estimated during a gait task through an inverse dynamics approach
Breve, E Succinto Racconto Del Viaggio, solenne Entrate, & ossequiosi Vasallaggi ... dell'Augustissimo Imperatore Leopoldo ... Principato Nel Mese di Giugno, e finito d'Ottobre L'Anno 1660 ... / Per opera, e studio di Lorenzo De Churelichz Araldo di Sua Maestà Cesarea
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Identification of distinct characteristics of postural sway in Parkinson's disease: a feature selection procedure based on principal component analysis.
No full textWe selected descriptive measures of the centre of pressure (CoP) displacement in quiet standing, by means of a procedure based on principal component analysis, in two groups particularly different in terms of postural behaviours, such as subjects with Parkinson's disease (PD) in the levodopa off and on states. We computed 14 measures of the CoP: 5 measures of CoP trajectory over the support surface, 3 measures that estimated the area covered by the CoP, 1 measure that estimated the principal CoP sway direction, 1 measure that quantified the CoP total power, 1 measure that estimated the variability of CoP frequency content and 3 measures of characteristic CoP frequencies [L. Rocchi, L. Chiari, A. Cappello, Feature selection of stabilometric parameters based on principal component analysis, Med. Biol. Eng. Comput. 42 (2004) 71-79; L. Rocchi, L. Chiari, F.B. Horak, Effects of deep brain stimulation and levodopa on postural sway in Parkinson's disease, J. Neurol. Neurosurg. Psychiatry, 73 (2002) 267-274]. The feature selection, independently applied to the measures obtained in the two groups, resulted in different principal component (PC) subspaces of the 14-dimension original data set (4 PCs in the off and 3 PCs in the on state to account for over 90% of the original variance), but in the same 5 CoP measures (selected features) needed to describe the different postural behaviours: root mean square distance; mean velocity; principal sway direction; centroidal frequency of the power spectrum; frequency dispersion. The five selected features were found to provide insight into the postural control mechanisms and to describe changes in postural strategies in the two groups of PD subjects, off and on levodopa. Thus, the five selected features may be recommended for use in clinical practice and in research, in the direction toward the definition of a standard protocol in quantitative posturography
First person – Alba Delrio-Lorenzo
No full textFirst Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Alba Delrio-Lorenzo is first author on ‘Sarcoplasmic reticulum Ca2+ decreases with age and correlates with the decline in muscle function in Drosophila’, published in JCS. Alba is a PhD student in the lab of Javier García-Sancho and María Teresa Alonso at the Instituto de Biología y Genética Molecular (IBGM), University of Valladolid, Spain, investigating the molecular mechanisms implicated in aging, particularly muscle aging.Peer reviewe
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