Audio-Visual Attractors for Capturing Attention to the Screens When Walking in CAVE Systems

International audienceIn four-sided CAVE-like VR systems, the absence of the rear wall has been shown to decrease the level of immersion and can introduce breaks in presence. In this paper it is investigated to which extent user's attention can be driven by visual and auditory stimuli in a four-sided CAVE-like system. An experiment was conducted in order to analyze how user attention is diverted while physically walking in a virtual environment, when audio and/or visual attractors are present. The foursided CAVE used in the experiment allowed to walk up to 9m in straight line. An additional key feature in the experiment is the fact that auditory feedback was delivered through binaural audio rendering techniques via non-personalized head related transfer functions (HRTFs). The audio rendering was dependent on the user's head position and orientation, enabling localized sound rendering. The experiment analyzed how different "attractors" (audio and/or visual, static or dynamic) modify the user's attention. The results of the conducted experiment show that audio-visual attractors are the most efficient attractors in order to keep the user's attention toward the inside of the CAVE. The knowledge gathered in the experiment can provide guidelines to the design of virtual attractors in order to keep the attention of the user and avoid the "missing wall". Index Terms: Audi

The ultrasound risk stratification systems for thyroid nodule have been evaluated against papillary carcinoma: a meta-analysis

Thyroid imaging reporting and data systems (TIRADS) are used to stratify the malignancy risk of thyroid nodule by ultrasound (US) examination. We conducted a meta-analysis to evaluate the pooled cancer prevalence and the relative prevalence of papillary, medullary, follicular thyroid cancer (PTC, MTC, and FTC) and other malignancies among nodules included in studies evaluating their performance. Four databases were searched until February 2020. Original articles with at least 1000 nodules, evaluating the performance of at least one TIRADS among AACE/ACE/AME, ACR-TIRADS, ATA, EU-TIRADS, or K-TIRADS, and reporting data on the histological diagnosis of malignant lesions were included. The number of malignant nodules, PTC, FTC, MTC and other malignancies in each study was extracted. For statistical pooling of data, a random-effects model was used. Nine studies were included, evaluating 19,494 thyroid nodules. The overall prevalence of malignancy was 34% (95%CI 21 to 49). Among 6162 histologically proven malignancies, the prevalence of PTC, FTC, MTC and other malignancies was 95%, 2%, 1%, and 1%, respectively. A high heterogeneity was found for all the outcomes. A limited number of studies generally conducted using a retrospective design was found, with possible selection bias. Acknowledging this limitation, TIRADSs should be regarded as accurate tools to diagnose PTC only. Proposed patterns and/or cut-offs should be revised and other strategies considered to improve their performance in the assessment of FTC, MTC and other malignancies

Gestural Control Of Wavefield synthesis

(Abstract to follow

MORFEO enters final design phase

MORFEO (Multi-conjugate adaptive Optics Relay For ELT Observations, formerly MAORY), the MCAO system for the ELT, will provide diffraction-limited optical quality to the large field camera MICADO. MORFEO has officially passed the Preliminary Design Review and it is entering the final design phase. We present the current status of the project, with a focus on the adaptive optics system aspects and expected milestones during the next project phase

The efficiency of xylem network in trees: a theoretical and experimental approach.

In the trees, water moves through a negative pressure gradient established between roots and leaves, through a network of xylem cells whose length can reach the order of magnitude of 100 meters in the higher plants on the planet. The grandeur of the transport system involves the need for the plant to implement some tricks to cope with the increasing hydraulic resistance related with the dramatic lengthening of the water path throughout the ontogeny. That is to say that the increase in plant height is accompanied by a consequent increase of the total hydraulic resistance within the xylem conduits. The most effective solution to contain the increase of hydraulic resistance seems to be the tapering of the conduit elements. The introduction by WBE (West, Brown, Enquist 1997, 1999) model of the hypothesis of universality of the degree of xylem conduit tapering in vascular plants, leads to introduce a threshold value of the "optimal" degree of tapering such that the hydraulic resistance of a path is approximately constant regardless of its length (the conduit is always potentially capable of growing). It was therefore suggested that the nature of hydraulic limitations to growth in plant height may be the result of a sub-optimality of the degree of tapering caused by the physical inability to increase cell diameter at the base indefinitely. Alternatively, it is possible that a sub-optimality of the overall transportation system can occur at some point of the development in height (and therefore in length and volume of xylem conduits) due to the impossibility of maintaining a state of optimum equilibrium of the conduction system, designed as a transport network optimized (Banavar, Maritan, Rinaldo 1999) when the volume of service inside the network and the hydraulic resistance resulting in the displacement of this volume, are both minimized in a logical solution of a minimum equilibrium bound problem. One of the objectives of this work has been put together two of the main models proposed recently to the attention of the scientific community (the WBE model and the model BMR) and to collect them in the development of a new unique model, to try to answer the fundamental question implied in this research topic: "which factors causes the plants to stop growing in height?".All'interno degli alberi, l'acqua si muove per mezzo di un gradiente negativo di pressione, che si instaura tra le radici e le foglie, attraverso una rete di cellule xilematiche la cui lunghezza può raggiungere l'ordine di grandezza di 100 metri nelle piante più alte del pianeta. Questa imponenza del sistema di trasporto comporta la necessità da parte della pianta di porre in atto degli stratagemmi per far fronte alla crescente resistenza idraulica che si sviluppa assieme al drastico allungamento di percorso idrico durante tutta l'ontogenesi. Vale a dire che l'aumento in altezza delle piante è accompagnato da un conseguente aumento di resistenza idraulica all'interno dello xilema. La più efficace delle soluzioni per contenere questo aumento di resistenza idraulica sembrerebbe essere la rastremazione degli elementi di conduzione. L'introduzione da parte del modello WBE (West, Brown, Enquist 1997, 1999) dell'ipotesi di universalità del grado di rastremazione dei condotti xilematici nelle piante vascolari, porta ad introdurre una soglia di rastremazione "ottimale" tale da rendere all'incirca costante la resistenza idraulica di un percorso a prescindere dalla sua lunghezza (potenzialmente sempre suscettibile di crescita). E' stato dunque ipotizzato che le limitazioni di natura idraulica alla crescita in altezza delle piante possano essere conseguenti all'insorgere di una sub-ottimalità del grado di rastremazione dei condotti proveniente dall'impossibilità fisica di aumentare indefinitamente il loro diametro alla base, od in alternativa che una sub-ottimalità generale del sistema di trasporto idraulico all'interno della pianta possa manifestarsi ad un certo punto dello sviluppo in altezza (e quindi in lunghezza ed in volume dei condotti xilematici) in conseguenza alla non possibilità di mantenimento di uno stato d'equilibrio ottimo del sistema di conduzione, pensato come una rete di trasporto ottimizzata (Banavar, Maritan, Rinaldo 1999) in cui il volume di servizio presente all'interno della rete e la resistenza idraulica conseguente allo spostamento di tale volume, siano entrambi minimizzati in una logica di soluzione d'equilibrio di minimo vincolato. Uno degli obiettivi di questo lavoro è stato mettere assieme due dei principali modelli recentemente proposti all'attenzione della comunità scientifica (il modello WBE ed il modello BMR) e di raccogliere nello sviluppo di un nuovo unico modello di scala le ipotesi e le intuizioni principali dei due, per cercare di dare una risposta alla domanda fondamentale sott'intesa in questo argomento di ricerca: "per l'insorgenza di quali fattori le piante smettono di crescere in altezza?"

“Urban Sounds”: an acoustical tour of Parma

The urban landscape is constantly changing: habits and customs of the people, transportation, residential areas and industrial ones change themselves. From “visual” point of view, the number of media that allow us to keep track of the changes (photo and video) increases but it’s not the same for the “acoustic” point of view. Almost all sounds and noises of an earlier eras have been lost. The idea behind this research, a collaboration between the Department of Industrial Engineering (University of Parma) and the municipal institution "Casa della Musica", is the sampling of the noise of the city, with state- of-art 3D audio recordings. The aim is dual: delivering to posterity an archive of recorded sound fields to document Parma in 2012 with advanced 3D surround recording techniques and creation of a “musical” Ambisonics composition for leading the audience through a virtual tour of the town