196,862 research outputs found
Forme dell'abitare. Un'analisi sociologica dello spazio borghese
No full textLo studio sulle Forme dell’abitare parte dal presupposto che tra il corpo e lo spazio vi sia una relazione di coappartenenza e si attivi una comunicazione che diviene fortemente significativa nella casa, luogo dell’identità e della memoria, dell’esperienza personale e intersoggettiva. L’autrice analizza i modelli abitativi che accompagnano la borghesia in ascesa dell’Ottocento e quella avanzata del Novecento; essi, infatti, restituiscono fedelmente e processualmente il “volto” dell’individuo e della classe sociale di appartenenza. Nella casa del borghese si collocano e si cristallizzano i valori in cui egli si identifica e che caratterizzano la sua vita privata e pubblica: razionalità, ordine, solidità familiare, relazione con Alter, definizione dei ruoli e condivisione dello status. Quello della casa è un bisogno individuale e collettivo che mobilita e contiene dinamiche fisiche, psichiche, antropologiche, sociali e culturali: l’abitazione garantisce – a livello simbolico e materiale – la “fissità” necessaria ad allontanare il senso di spaesamento e sradicamento che caratterizza l’individuo-flâneur contemporaneo
Genetic improvement strategies in buffalo.
No full textBreeding and official selection activity in any country depends on the economic importance of the considered livestock, therefore of the products that can be obtained from it. The first step in the breeding and selection activity with regard to any dairy livestock is the milk recording of the productivity of each yielding animal. The results, when appropriately merged with the genealogy data, allow a definition of the milk genetic merit of each animal, in particular of the bull, for which we have no other milk record except the production of his progeny. The importance of animal recording for the activity of selection is well recognized all over the world and is demonstrated by the fact that in most countries such activity is at least partially financed by governments, which consider it an important means for the improvement of animal production. An international non governmental organization, the International Committee for Animal Recording (ICAR) has been active for over thirty years in the field of promotion and standardization of animal recording. The highest proportion of milk recorded buffaloes, in fact, is found in Italy (27.8%), in Iran is 4.5 %, while in other countries the recorded buffaloes are about 1% of total dairy females (Turkey, Egypt) or less. We have high percents of recorded buffaloes in Bulgaria, Syria and Greece, where the buffalo population is disappearing. The productivity in other countries is lower than in Italy, considering that only in Italy there was a very long work of recording, selection and genetic improvement, health, feeding and livestock system rising. Also milk composition was improved in Italy in few years, with mean protein percentage from 4.4 to 4.8 and fat percentage from 7.3 to 8.1 without any selection of this character. Moreover the possibilities of genetic improvement for milk quantity and quality will be higher, if the selection pressing will be increased reducing the number of bred females. So, just now there are in Italy many females producing more than 5,000 kg milk for lactation (270 days). Therefore the selection will be directed for the improvement of the yield of mozzarella cheese, not simply for milk production, because the farm income actually is resulting first from mozzarella cheese, alter from the selling of pregnant heifers, at the last from beef (Borghese, 2004). A consistent number of recorded buffaloes is obviously found in countries with the highest presence of buffaloes (India, Pakistan and Egypt) which signifies that these countries have also taken steps towards implementing an organized milk improvement activity, on a solid scientific and technical basis
Un nuovo disegno di Mario Asprucci per il Museo dei Gabi in Villa Borghese
No full textL'autore ricostruisce le vicende della progettazione del Museo dei Gabi in Villa Borghese a Roma alla luce di un inedito, quanto importante, disegno di presentazione attribuito a Mario Asprucci. Le vicende, legate alla musealizzazione delle statue ritrovate a Gabi da Gavin Hamilton nel Pantano dei Grifi, permette di precisare la complessità dell'elaborazione del linguaggio neoclassico da parte dell'architetto Asprucci. Inoltre l'autore analizza l'album dei disegni del Museo dei Gabi del Museo di Roma di Palazzo Braschi, già attribuito a Giuseppe Valadier, attribuendolo più correttamente a Cristoforo Unterpregher.The author reconstructs the events of the design of the Gabi Museum in the Villa Borghese in Rome in the light of an unpublished, yet important, presentation drawing attributed to Mario Asprucci. The events, related to the musealisation of the statues found in Gabi by Gavin Hamilton in the Pantano dei Grifi, allow us to clarify the complexity of architect Asprucci's elaboration of neoclassical language. In addition, the author analyses the album of drawings in the Gabi Museum of Rome's Palazzo Braschi, formerly attributed to Giuseppe Valadier, attributing it more correctly to Cristoforo Unterpregher
A new and reliable Poisson noise estimator for radiographic images
No full textDigital images in general, and radiographies in particular, are mainly affected by photon counting noise. In this paper, we provide a method to estimate the gain of the imaging sensor and the variance of the photon counting noise associated to each image grey level. This is useful to multiple scopes, like reverse engineering and denoising
“El Sistema” in Italia: studio di casi multipli dell’adattamento del progetto venezuelano delle orchestre giovanili in quattro ‘nuclei’ italiani
No full textIl lavoro di ricerca sul progetto venezuelano d’El Sistema con approccio quali-quantitativo affronta un fenomeno poco conosciuto, che arriva e si adatta anche in Italia, su quasi tutto il territorio nazionale, a partire dal 2010, e punta alla costruzione di una rete di orchestre giovanili e alla diffusione, ad ampio raggio, dell’educazione musicale gratuita. Esso rappresenta una novità anche in Italia, soprattutto per il numero di bambini coinvolti e per l’idea di ‘rete’ da creare tra le diverse realtà locali. Ad oggi in Venezuela il dispositivo in esame coinvolge 400.000 soggetti, in Italia esistono 49 Nuclei che coinvolgono individui di età compresa tra i 3 e i 25 anni, raggiungendo diverse centinaia di soggetti.
Lo studio di dottorato, dopo una dettagliata presentazione storico-politica del dispositivo, riflette criticamente sulle sue dimensioni pedagogiche: il collettivo-orchestrale come ‘nuova condizione’ di apprendimento ed esperienza in senso lato, le sue implicazioni, caratteristiche ed organizzazione; la dimensione spirituale della musica e sua forza coesiva; la sperimentazione didattica unita alle più grandi tradizioni metodologiche occidentali, e al dialogo ‘implicito’ che con esse si instaura, in particolare col metodo Suzuki; alcuni degli aspetti che fanno d’ES un progetto efficace; le criticità e i dissensi che sono nati in merito al modello originario e al suo adattamento e alla sua diffusione nel mondo.
La ricerca di tipo esplorativo-conoscitivo si sviluppa con un disegno a due fasi. La prima, di ‘ricerca descrittiva’, è finalizzata a ‘mappare’ El Sistema in Italia: una ricognizione della ‘popolazione’ (distribuzione e caratteristiche dei Nuclei) capace di ‘fotografare’ la situazione italiana, di conoscerne l’organizzazione e le dinamiche. Le domande di ricerca, infatti, riguardano l’organizzazione nazionale e sono finalizzate alla conoscenza del processo che ha portato alla nascita e allo sviluppo del progetto venezuelano in Italia: chi sono, cioè, gli enti propulsori; quale il modo con cui viene gestito e da chi; quali le caratteristiche dei Nuclei.
La seconda fase, di ‘studio di casi multipli’, prevede lo studio e il monitoraggio, in chiave longitudinale, di quattro gruppi orchestrali, scelti secondo una serie di requisiti definiti in fase di studio dei dati ottenuti dalla prima fase della ricerca. In particolare, questa seconda fase si propone un versante descrittivo di ciascun Nucleo, dal punto di vista logistico, organizzativo, didattico.
Un ulteriore livello di ricerca sviluppa un disegno ‘quasi sperimentale’, a due gruppi, per verificare l’impatto d’El Sistema nel creare e mantenere ‘senso di comunità in un contesto di apprendimento’.
Il piano longitudinale di analisi ha comportato due somministrazioni (pre/post): la seconda, a distanza di un anno dalla prima, per verificare il cambiamento nei ragazzi dopo un anno di attività in orchestra. Il costrutto di ‘senso di comunità in un contesto di apprendimento’ è stato identificato in due dimensioni: - la ‘connessione’ tra i ragazzi (scambio e reciprocità); - l’interazione all’interno della comunità finalizzata alla comprensione e la misura in cui gli obiettivi dell’apprendimento vengono soddisfatti all’interno del contesto classe. Lo strumento utilizzato per verificare la suddetta ipotesi è la Classroom Community Scale (2002) di Alfred P. Rovai
Transient reversal of the stretch reflex in human arm muscles
No full text1. Load perturbation responses can violate the law of reciprocal innervation between antagonist muscles under particular conditions. Thus flexor and extensor muscles of wrist and elbow joints are reflexly coactivated by the impact of a ball on the hand during a catching task. The aim of this study was to determine whether reflex coactivation can be preset within the central nervous system (CNS) or whether it is entirely due to the peripheral stimulus. To this end, we studied the behavior of stretch reflex responses of arm muscles evoked by torque motor perturbations applied before and during the catching task. 2. Subjects were instructed to catch a ball dropped from 1.6 m. A torque motor delivered perturbations to the elbow joint, resulting in angular motion at both elbow and wrist joints because of their dynamic mechanical coupling. Two series of experiments were performed that differed in the perturbation waveform. In the first series, a single torque pulse could be randomly applied at different times during the task. The corresponding responses were recovered by subtracting the average of the unperturbed trials from the averages of perturbed trials. In the second series of experiments, a train of pseudorandom pulses was applied continuously during each trial. The time-varying impulse responses were computed at 20-ms intervals by cross-correlation methods. 3. The pattern of the short-latency electromyographic responses evoked by either single pulses or pseudorandom perturbations obeyed the law of reciprocal innervation of antagonist muscles under basal conditions. However, the pattern of the responses evoked by the same perturbations around the time of ball impact on the hand consisted of a substantial coactivation of both stretched and shortening muscles. Reflex coactivation resulted from response patterns that differed at different joints. At the elbow, reflex coactivation resulted from a transient reversal of the direction of the short-latency responses of flexor muscles, with little changes of the responses of extensor muscles. At the wrist, instead, reflex coactivation resulted from simultaneous changes in the response waveform of both flexor and extensor muscles. 4. The peripheral conditions associated with the applied perturbations were constant before the time of ball impact. Thus, because the changes of the stretch reflex responses began before that time, they must have been generated within the CNS. It is here hypothesized that the reversal of the reflex responses is centrally gated by switching from the pathways of reciprocal inhibition to those of coactivation of antagonist alpha-motoneurons.(ABSTRACT TRUNCATED AT 400 WORDS
Denoising of digital radiographic images with automatic regularization based on total variation
No full textWe report here a principled method for setting the regularization parameter in total variation filtering, that is based on the analysis of the distribution of the gray levels on the noisy image. We also report the results of an experimental investigation of the application of this framework to very low photon count digital radiography that shows the effectiveness of the method in denoising such images. Total variation regularization leads to a non-linear optimization problem that is solved here with a new generation adaptive first order method. Results suggest a further investigation of both the convergence criteria and/or the scheduling of the optimization parameters of this method
Internal models of limb geometry in the control of hand compliance
No full textThe aim of this article is to describe the role of some neural mechanisms in the adaptive control of limb compliance during preplanned mechanical interaction with objects. We studied the EMG responses and the kinematic responses evoked by pseudorandom perturbations continuously applied by means of a torque motor before and during a catching task. The temporal changes of these responses were studied by means of an identification technique for time-varying systems. We found a transient reversal of EMG stretch reflex responses centered on the time of ball impact on the hand; this reversal results in a transient coactivation of antagonist muscles at both the elbow and the wrist. The kinematic responses describe the relation between torque input and position output. Thus, they provide a global measure of limb compliance. The changes in limb compliance during catching were quantified by computing error criteria either in the Cartesian coordinates of the hand or in the angular coordinates of the elbow and wrist joints. We found that only the hand compliance in Cartesian coordinates is consistently minimized around impact, in coincidence with the transient reversal of the stretch reflex responses. By contrast, the error criteria expressed in the angular coordinates of the joints have a variable time course and are not minimized around impact. It is known that hand compliance depends on both the pattern of muscle activities and the geometrical configuration of the limb. Therefore, the lack of consistent correlation between the changes in hand compliance and the changes in the geometrical configuration of the limb during catching indicates that the gating of the stretch reflex responses around impact time is based on an internal model of limb geometry
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