171 research outputs found
Thermodynamic Limit and Dispersive Regularisation in Matrix Models
We show that Hermitian matrix models support the occurrence of a new type of
phase transition characterised by dispersive regularisation of the order
parameter near the critical point. Using the identification of the partition
function with a solution of a reduction of the Toda hierarchy, known as
Volterra system, we argue that the singularity is resolved by the onset of a
multi-dimensional dispersive shock of the order parameter in the space of
coupling constants. This analysis explains the origin and mechanism leading to
the emergence of chaotic behaviours observed in M^6 matrix models and extends
its validity to even nonlinearity of arbitrary order.Comment: 8 pages, 7 figures. Sections have been reorganised and expanded.
Order of figures and captions have been modified. Accepted for publication in
Physical Review
Models of information systems devoted to medical-imaging labs: an experience in the CNR clinical physiology institute
At the end of the 1990s, the SPERIGEST project, supported by the Italian Health Ministry, and fully developed at the Institute of Clinical Physiology, established an operative integrated clinical and healthcare information system. Continuously evolving and dynamically optimising procedures and protocols solve problems of: harmonisation of instrumentation of different brands; management of multimedia data provided by different medical imaging labs; satisfaction of both clinical and research needs; legal and economical requirements; user-friendship of the system. A ten years experience shows positive approach by medical and healthcare operators, coordinated activity, higher efficiency, simplified procedures, major concentration on medical decision-making
Information systems for medical imaging labs: the experience of the CNR Clinical Physiology Institute
In the late 1990s the CNR Clinical Physiology Institute was entrusted with the "SPERIGEST" project, granted by the Italian Health Ministry. Among the technical challenges of the project, the following issues were faced: 1) the definition of a system architecture able to conjugate a centric view, as required by data integration needs, with flexibility and modularity in order to satisfy the different healthcare environments; 2) the creation of local information systems devoted to the management of each single laboratory activity; 3) the creation of a suitable network to exchange information both inside and outside the hospital; 4) the overcoming of safety and security issues in the treatment of healthcare data; 5) the data processing for extracting knowledge from the archived data and for supporting the diagnostic/treatment process; 6) the education of healthcare personnel; 7) the adoption of standards for both storage and distribution of data. An hospital information system was developed according to a three layers mode
Information systems for the management of clinical, administrative and government data of clinical imaging laboratories
Integrated network-based medical information systems are in continuous development an d evolution, furthered by the ongoing technology: the aim is to limit healthcare expend iture, while facing the increase of the demand of health services, as a result of the improvement of socialeconomic conditions, ageing of the population, and progress in medical knowledge and technologies. Today the discipline of OHealth Informaticso takes care of the design and the impleme ntation of information systems, to provide to the organization, processing, integration, storage, distribution and management, of the clinical and administrative data
Models of Information Systems devoted to Medical Imaging Labs: an experience in the CNR Clinical Physiology Institute
abstract for the paper presentation about the decennal experience at IFC on information systems developped for medical imaging labsabstract per la presentazione relativa alla decennale esperienza presso IFC sui sistemi informativi sviluppati per uso dei laboratori dedicati all\u27imaging clinico e di ricerca medic
Information systems for medical imaging labs: the experience of the CNR Clinical Physiology Institute
Local information systems, devoted to the management of the clinical and healthcare activity in laboratories for biomedical imaging, has been realized in IFC. Herein is a presentation of the main results obtained after a ten years development and employment of such a complex information system
Information Systems for the Management of Clinical, Administrative and Government Data of Clinical Imaging Laboratories
The integrated clinical and healthcare information system, developed at the CNR Clinical Physiology Institute, undergoes to updated and upgraded procedures and protocols, by solving problems of: harmonization of instrumentation of different brands; management of multimedial data provided by different medical imaging labs; satisfaction of both clinical and research needs as well as legal and economical requirements; user-friendship of the provided tools. Peculiar attention has been paid to the management of the laboratories devoted to biomedical imaging: medical and healthcare operators have coworked with engineers, to get a system able to guarantee coordinated activity, higher efficiency, simplified procedures, major concentration onto the medical decision-making issues, by supporting conventional techniques as well as new hybrid imaging technologies.Il sistema informativo per uso clinico e sanitario, sviluppato presso l\u27Istituto di Fisiologia Clinica del CNR, e\u27 in continuo aggiornamento e sviluppo di procedure e protocolli, che risolvano problemi relativi a: armonizzazione di strumentazione prodotta da diversi marchi commerciali e non; gestione dei dati multimediali forniti dai vari laboratori di imaging clinico; soddisfazione delle esigenze di ricerca e cliniche nonche\u27 deei requisiti di legalita\u27 ed economicita\u27; facilita\u27 d\u27uso degli strumenti proposti all\u27utente. Particolare attenzione e\u27 stata dedicata al "governo" dei laboratori di imaging medicale, e i vari operatori sanitari hanno collaborato con quelli tecnologici per realizzare un sistema capace di garantire un\u27attivita\u27 coordinata, piu\u27 elevata efficienza, procedure semplificate, maggiore concentrazione sulla "decisione" medica, sia dando sostegno alle tradizionali tecniche di acquisizione che alle innovative tecniche ibride
Study for a portable IR sensor to detect the blood temperature during coronary bypass implantation
The objective of this research was to investigate the possibility of using an infrared prototype device for the detection of the blood temperature during a surgical operation for coronary bypass implantation. The correlation between the fluid temperature time behavior and the fluid flow rate was demonstrated. Each blood vessel acts like a thermal wave emitter, so the amount of heat is proportional to the blood flow detected by the IR sensor. The idea was to design a low cost portable device with the advantage that it can be placed near the region of interest. We chose a pyroelectric sensor for its high-quality cost ratio. Because this kind of sensor detects only a variable infrared source, we used an electromechanical chopper for modulating the radiation. It consists of an electronic shutter whose opening speed is controlled by an astable multivibrator. The output signal was analyzed using a dedicated electronic circuit including a bandpass filter and an amplifier; then an acquisition board was employed for capturing and displaying the signal using a PC. Prototype assessment was made with laboratory equipment and in vivo measurements were made during surgical operation on a small pig
Contactless measurements of liquid sample electrical conductivity for estimating specific absorption rate in MR applications
Specific Absorption Rate (SAR) is the dosimetric parameter currently used as standard in the safety recommendation reports [1] for Magnetic Resonance Imaging (MRI) procedures. With the employment of MR systems with high field strengths (from 3T up to 8T), the study of the potential radiofrequency (RF) effects on the biological tissues due to higher radiofrequency, has a particular relevance [2]. Bottomley et al. [3] described a theoretical method to estimate the radiofrequency power deposition during MR exams, based on the sample geometry, the magnetic field radiofrequency, the MR sequence used (its pulse width, repetition time and flip angle) and, finally, the sample electrical conductivity. In this work we develop a liquid sample dielectric properties measurement system based on the evaluation of the resonance frequency and quality factor of a resonant circuit composed by a home-made coil. The major advantage of this method is the contactless between the liquid sample and the measurement electrode. We perform the measurement at 63.85MHz, corresponding to a 1.5T clinical MR environment, but this method can be used for measurements in the whole RF range, tuning the resonant circuit on the desired frequency
Concevoir des systèmes de culture adaptés aux agricultures familiales. Le cas du semis direct dans l'État du Parana (Brésil)
Au sud du Brésil, une longue trajectoire de recherche et de développement a donné lieu à une large utilisation de systèmes de culture en semis direct par les agriculteurs, y compris en agriculture familiale, ce qui n'est pas commun au niveau international. Deux enquêtes menées en 2004 et 2013 auprès des exploitations familiales de la région d'Irati (Parana, Brésil) montrent jusqu'à quel point elles ont adopté ces systèmes et leurs trois principes de base. Si l'utilisation du semoir à semis direct s'est généralisée, les rotations et les plantes de couverture sont moins diversifiées que celles promues par la recherche. Les rotations se sont simplifiées et les plantes de couverture ont surtout été utilisées pour produire du fourrage pour les troupeaux laitiers, activité en fort développement. Par ailleurs, la plupart des agriculteurs ont recours périodiquement au labour pour gérer divers problèmes agronomiques auxquels ils font face. Les agriculteurs familiaux ont donc adapté dynamiquement, plutôt qu'adopté le modèle de semis direct proposé par la recherche, à leurs objectifs, ressources et contraintes spécifiques, en tenant compte des conditions très variables dans lesquelles ils opèrent. Ce faisant, ils répondent plus aux facteurs et aux conditions économiques de court terme (prix de vente, rentabilité) ou opérationnels (disponibilité de semences de couverture et fourragères, facilité d'intervention) qu'à l'optimisation des performances agronomiques et à l'amélioration de la fertilité du sol à long terme, mises en avant par la recherche. Mieux répondre à la diversité des contraintes, besoins et objectifs des agriculteurs familiaux implique que la recherche soit capable et désireuse de mettre en oeuvre, à l'avenir, des démarches de co-conception de systèmes de culture et de production innovants en partenariat avec eux et avec les autres acteurs clés du développement agricole. (Résumé d'auteur
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