240 research outputs found
Laser interferometry for straightness measurements in a weakly controlled environment
No full textAbstract: Straightness measurements for the geometrical inspection of machining tools have been operated in a weakly controlled environment (concerning temperature, pressure, humidity and induced mechanical vibrations) with reference to industrial manufacturing departments. Measurements have been performed by means of a Wollaston prism laser interferometer. A first experimental characterization of this instrumentation has been operated by repeatability tests conducted in controlled and not controlled environments, considering different relative positions for the interferometer and the laser head. Then a calibration diagram has been constructed, assessing the accuracy and the instrumental uncertainty in the case of displacement measurements in a plane perpendicular to the laser beam direction. In a second stage a suitable method has been developed to estimate the uncertainty level associated to straightness measures operated by the laser interferometric technique and also by traditional instrumentation, such as taut-wire and microscope and precision level. Measurement uncertainty is estimated by means of the Monte Carlo Method and according to standards. Measures obtained by the laser interferometric method prove to be affected by higher levels of uncertainty than those coming from traditional approaches
Incertezza di misura nella caratterizzazione dinamica di dispositivi antivibranti gomma-metallo
No full text
Valutazione dell’incertezza nelle misure della rigidezza dinamica di dispositivi antivibranti
No full textSlow-oscillatory Transcranial Direct Current Stimulation Modulates Memory in Temporal Lobe Epilepsy by Altering Sleep Spindle Generators: A Possible Rehabilitation Tool.
No full textBACKGROUND:
Temporal lobe epilepsy (TLE) is often associated with memory deficits. Given the putative role for sleep spindles memory consolidation, spindle generators skewed toward the affected lobe in TLE subjects may be a neurophysiological marker of defective memory. Slow-oscillatory transcranial direct current stimulation (sotDCS) during slow waves sleep (SWS) has previously been shown to enhance sleep-dependent memory consolidation by increasing slow-wave sleep and modulating sleep spindles.
OBJECTIVE/HYPOTHESIS:
To test if anodal sotDCS over the affected TL prior to a nap affects sleep spindles and whether this improves memory consolidation.
METHODS:
Randomized controlled cross-over study. 12 people with TLE underwent sotDCS (0.75 Hz; 0-250 μV, 30 min) or sham before daytime nap. Declarative verbal and visuospatial learning were tested. Fast and slow spindle signals were recorded by 256-channel EEG during sleep. In both study arms, electrical source imaging (ESI) localized cortical generators. Neuropsychological data were analyzed with general linear model statistics or the Kruskal-Wallis test (P or Z < 0.05), and neurophysiological data tested with the Mann-Whitney t test and binomial distribution test (P or Z < 0.05).
RESULTS:
An improvement in declarative (P = 0.05) and visuospatial memory performance (P = 0.048) emerged after sotDCS. SotDCS increased slow spindle generators current density (Z = 0.001), with a shift to the anterior cortical areas.
CONCLUSIONS:
Anodal sotDCS over the affected temporal lobe improves declarative and visuospatial memory performance by modulating slow sleep spindles cortical source generators. SotDCS appears a promising tool for memory rehabilitation in people with TLE
Empowering Conditions for Good Water Governance - a Sustainable Model: Vilanculos Case Study (Mozambique)
No full textThis article shows the results of the project Empowering conditions for good water governance—a sustainable model:
Vilanculos case study (Mozambique), co-financed by the European Community. This project had the aim of improving sanitary
conditions and increasing economic and financial sustainability of water services for the population of Vilanculos. The project has
been developed and deployed with cooperation between Acque del Chiampo (an Italian water utility, near Vicenza), the University of
Brescia and the Vilanculos public water service utility, Empresa Moçambicana de Agua (EMA). The paper reports analytical praxis
for water distribution measurements, capable of providing essential data about the water network performances, to assess the
eventual need for actions in order to solve possible and effective problems of the water service. These practices involve flow and
pressure analyses, pinpointing of the network’s criticalities and leakages by in-situ inspections along the network, managing the
valves together with water service utility, as well as the use of a water distribution model to simulate the effects of the proposed
interventions and specific software to automatically register bills and payments
Completely reversible agranulocytosis in a multiple myeloma patient treated with Thalidomide-dexamethasone
No full textFrom Alzheimer's disease retrogenesis: a new care strategy for patients with advanced dementia
No full textThere is evidence that exercise may reduce the progressive cognitive dysfunction of Alzheimer's disease (AD). However, no previous investigation has studiethe acute effects of adapted games (AG) on patients with AD. The aim of this study was to examine the acute effects of AG on the agitated behavior (rating scale Agitated Behavior Rating Scale [ABRS]) and cognitive performance (Test for Severe Impairment [TSI]) of patients with advanced dementia. Twenty patients (83±4 yrs) participated in AG and placebo activities (PL). Agitated behavior and cognitive performance were compared before and after 30 minutes of AG and PL. In the hour after the AG, agitated behavior decreased by ∼4 ABRS points and cognitive performance increased by ∼5 TSI points. On the contrary, after PL we found no change in agitated behavior or cognitive performance. Our data indicate that AG can momentarily reduce agitated behavior and increase the cognitive performance in participants with AD
Road profile excitation on a vehicle measurements and indoor testing using a four-post rig
No full textThe role of reward-based motivation in motor learning and performance
No full textIl comportamento umano è fortemente influenzato dalla motivazione che consente il perseguimento degli obiettivi sostenendo un'ispezione efficiente dell'ambiente circostante e consentendo l'esecuzione delle azioni motorie più convenienti per interagire con esso. La motivazione può essere manipolata con successo semplicemente somministrando rinforzi o punizioni in cambio di prestazioni comportamentali. Lo scopo di questa ricerca è stato quello di studiare come l'apprendimento di un modello comportamentale visuo-motorio possa essere influenzato da diversi contesti motivazionali. A questo scopo, abbiamo sviluppato un protocollo di training computerizzato in grado di indurre l'apprendimento di schemi motori specifici ed abbiamo esaminato le prestazioni in questa nuova attività in quattro diversi gruppi con differenti gradi di coinvolgimento motivazionale. I quattro protocolli adottati nei diversi gruppi sono stati: 1) senza alcun tipo di ricompensa o di informazioni sulla prestazione (Esperimento 1), 2) con un errore di retroazione, segnalando le prove con scarso rendimento (Esperimento 2), 3) con un incentivo monetario indicante la disponibilità di un premio variabile in funzione dell’accuratezza della prestazione nella prova che sarebbe seguita (Esperimento 3), 4) con un feedback monetario, offrendo una ricompensa variabile immediatamente dopo le prove con una performance accurata (Esperimento 4). La nuova attività visivo-motoria da apprendere consisteva nel muovere il dito indice sopra un potenziometro al fine di mantenere un cursore entro i confini di un percorso curvilineo che scorreva sulla schermo del computer. Il protocollo è stato caratterizzato da: 9 sedute di allenamento in giorni consecutivi, 3 sedute di ritenzione e 2 sessioni di test in tempi diversi dall'ultimo giorno di allenamento. In ogni sessione i partecipanti dovevano completare 160 prove. Negli esperimenti 3 e 4 i segnali di ricompensa venivano consegnati sia nel corso delle sessioni di allenamento che durante le sessioni di ritenzione. Nessun premio è stato consegnato durante le sessioni di test. Una prima analisi completa dei dati è stata effettuata attraverso l’analisi della varianza a misure ripetute (ANOVA) con Esperimento (da 1 a 4) come fattore tra soggetti e sessione come fattore entro soggetti. Nel complesso, il “Tempo In” (il tempo trascorso dal cursore all'interno del percorso in movimento) è aumentato notevolmente tra le sessioni, raggiungendo un plateau solo dopo 7 giorni dall'inizio dell’allenamento. Confrontando a livello globale la prestazione tra gli esperimenti, è stato chiaro che i punteggi più alti sono stati ottenuti dai partecipanti nell’Esperimento 4 ed i punteggi più bassi sono stati ottenuti nell'Esperimento 1. I nostri dati hanno mostrato che, con un alto impegno motivazionale, l’apprendimento motorio sviluppato in precedenza ed i suoi effetti sono stati più duraturi rispetto alla condizione in cui non era presente alcun feedback. In linea con la natura traslazionale di questo progetto, il passo successivo sarà quello di elaborare nuovi protocolli di allenamento visuo-motorio, con feedback gratificanti, al fine di 1) promuovere un più veloce ed efficiente recupero delle funzioni visuo-motorie nei pazienti con ictus cerebrale, 2) aumentare l'energia motoria e, in questo modo, facilitare l'applicazione e l'efficacia della maggior parte dei programmi di riabilitazione con pazienti con malattia di Parkinson.Human behaviour is crucially driven by motivation, which allows the pursuit of goals by supporting an efficient inspection of the surrounding environment and by enabling execution of the more convenient motor actions to interact with it. Motivation can be successfully manipulated by simply delivering rewarding (or punishing) consequences in return to behavioural performance. The aim of this research was to study how the learning of a visuo-motor behavioural pattern may be influenced by different motivational contexts. To this purpose, we developed a computerized training protocol able to induce learning of specific motor patterns and examined performance in this new task in four different groups with different degrees of motivational engagement. The four protocols adopted in the different groups were: 1) without any kind of reward or feedback information (Experiment 1); 2) with an error feedback, signaling trials with poor performance (Experiment 2); 3) with a monetary incentive signaling the availability of a variable prize in turn for accurate performance in the forthcoming trial (Experiment 3); 4) with a monetary feedback, delivering a variable reward immediately after trials with an accurate performance (Experiment 4). The new visuo-motor task to be learned, required to move the index finger over a potentiometer in order to keep a cursor within the boundaries of a curvilinear path sliding across the computer screen. The protocol was characterized by: 9 sessions of training in consecutive days, 3 retention sessions and 2 test sessions at different time lags from the last training day. On each session participants had to complete 160 trials. In Experiments 3 and 4 reward signals were delivered during both training and retention sessions. No reward was delivered during the test sessions. A first, comprehensive data analysis was carried out through a repeated measures analysis of variance (ANOVA) with Experiment (1 to 4) as the between-subjects factor and Session as the within-subjects factor. Overall, Time In performance (the time spent by the cursor inside the moving path) increased significantly across sessions, reaching a plateau only after 7 days from the beginning of training. By comparing the overall level of performance across experiments it was clear that the highest scores were obtained by participants in Experiment 4 and the lowest scores were obtained in Experiment 1. Our data showed that, under high motivational engagement, motor learning developed earlier, and its effects were longer lasting compared to the condition in which no feedback was present. In line with the translational nature of this project, the next step will be to devise new protocols of visuo-motor training grounded on these findings, pivoting on the delivery of rewarding feedbacks 1) to promote faster and more efficient recovery of visuo-motor functions in patients with cerebral stroke 2) to increase motor energy and, in this way, facilitate the application and improve the efficacy of most rehabilitation programs with patients with Parkinson’s disease
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