9,097 research outputs found
The Role of rescue therapies in the treatment of severe ARDS
ARDS is characterized by a non-cardiogenic pulmonary edema with bilateral chest radiograph opacities and hypoxemia refractory to oxygen therapy. It is a common cause of admission to the ICU due to hypoxemic respiratory failure requiring mechanical ventilation. Corticosteroids are not recommended in ARDS patients. Rescue therapies alleviate hypoxemia in patients unable to maintain reasonable oxygenation: recruitment maneuvers, prone positioning, inhaled nitric oxide, high-frequency oscillatory ventilation, and extracorporeal membrane oxygenation improve oxygenation, but their impact on mortality remains unproven. Restrictive fluid management seems to be a favorable strategy with no significant reduction in 60-d mortality. Future studies are needed to clarify the efficacy of these therapies on outcomes in patients with severe ARDS, and institution of these therapies may be considered on a case-by-case basis
Multifunction MMIC For Miniaturized Solid State Switch Matrix
This paper describes a new multifunction MMIC expressly designed for a reconfiguration matrix equipment.This MMIC has been developed using a standard PHEMT process and includes two switches,a totally switchable-off amplifier and a temperature compensation circuit.The complete circuit has also been designed to interface a standard CMOS control level. Performed simulations and obtained results demonstrate the effectiveness of this approach in reaching compactness and reliability of satellite equipment
Dynamical fluctuations in an exactly solvable model of spin glasses
In this work we calculate the dynamical fluctuations at O(1/N) in the low
temperature phase of the spherical spin glass model. We study the
large-times asymptotic regimes and we find, in a short time-differences regime,
a fluctuation dissipation relation for the four-point correlation functions.
This relation can be extended to the out of equilibrium regimes introducing a
function which, for large time , we find scales as as in
the case of the two-point functions.Comment: Latex, 8 page
Phase Retrieval for Sparse Signals: Uniqueness Conditions
In a variety of fields, in particular those involving imaging and optics, we
often measure signals whose phase is missing or has been irremediably
distorted. Phase retrieval attempts the recovery of the phase information of a
signal from the magnitude of its Fourier transform to enable the reconstruction
of the original signal. A fundamental question then is: "Under which conditions
can we uniquely recover the signal of interest from its measured magnitudes?"
In this paper, we assume the measured signal to be sparse. This is a natural
assumption in many applications, such as X-ray crystallography, speckle imaging
and blind channel estimation. In this work, we derive a sufficient condition
for the uniqueness of the solution of the phase retrieval (PR) problem for both
discrete and continuous domains, and for one and multi-dimensional domains.
More precisely, we show that there is a strong connection between PR and the
turnpike problem, a classic combinatorial problem. We also prove that the
existence of collisions in the autocorrelation function of the signal may
preclude the uniqueness of the solution of PR. Then, assuming the absence of
collisions, we prove that the solution is almost surely unique on 1-dimensional
domains. Finally, we extend this result to multi-dimensional signals by solving
a set of 1-dimensional problems. We show that the solution of the
multi-dimensional problem is unique when the autocorrelation function has no
collisions, significantly improving upon a previously known result.Comment: submitted to IEEE TI
La LIM in classe. Un’ipotesi di lavoro per la formazione degli insegnanti
Il lavoro si focalizza sulla formazione degli insegnanti all’uso della LIM. Presenta un intervento per la progettazione e sperimentazione di risorse didattiche basato sul modello del networked lesson study, una modalità di ricerca e produzione di contenuti didattici incentrato sul lavoro in piccoli gruppi e sull’impiego di tecniche di reciproca osservazione per la formazione degli insegnanti. Il modello è stato ripreso, adattato e sperimentato nel progetto AMELIS, finanziato nell’ambito dell’Iniziativa INNOVASCUOLA 2008-20010. Il progetto ha coinvolto dieci scuole tra Toscana e Umbria ed è stato seguito da un team di ricercatori costituito da Maria Ranieri, Giovanni Bonaiuti e Antonio Fini.The paper focuses on teachers’ training to the use of the interactive witheboard. It discusses an intervention for the design and the testing of the educational resources based on the networked lesson study model (NLS). The NLS is a research and production approach to the development of educational materials which is centered on teamwork and on the use of mutual observation techniques for the training of the teachers. This model has been adopted, adapted and tested within the AMELIS project, funded within the initiative INNOVASCUOLA 2008-20010. The project involved a network of ten school distributed between Tuscany and Umbria. The research team which leaded the research project was made up of Maria Ranieri, Giovanni Bonaiuti and Antonio Fini (University of Florence)
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