Statistical analysis of the trigger algorithm for the NEMO project

We discuss the performances of a trigger implemented for the planned neutrino telescope NEMO. This trigger seems capable to discriminate between the signal and the strong background introduced by atmospheric muons and by the beta decay of the K-40 nuclei present in the water. The performances of the trigger, as evaluated on simulated data are analyzed in detail.Comment: Published in the Proceedings of the "I Workshop of Astronomy and Astrophysics for Students", Eds. N.R. Napolitano & M. Paolillo, Naples, 19-20 April 2006 (astro-ph/0701577

Implementation of the trigger algorithm for the NEMO project

We describe the implementation of trigger algorithm specifically tailored on the characteristics of the neutrino telescope NEMO. Extensive testing against realistic simulations shows that, by making use of the uncorrelated nature of the noise produced mainly by the decay of K-40 beta-decay, this trigger is capable to discriminate among different types of muonic events.Comment: Published in the Proceedings of the "I Workshop of Astronomy and Astrophysics for Students", Eds. N.R. Napolitano & M. Paolillo, Naples, 19-20 April 2006 (astro-ph/0701577

Star Formation Rates for photometric samples of galaxies using machine learning methods

Star Formation Rates or SFRs are crucial to constrain theories of galaxy formation and evolution. SFRs are usually estimated via spectroscopic observations requiring large amounts of telescope time. We explore an alternative approach based on the photometric estimation of global SFRs for large samples of galaxies, by using methods such as automatic parameter space optimisation, and supervised Machine Learning models. We demonstrate that, with such approach, accurate multi-band photometry allows to estimate reliable SFRs. We also investigate how the use of photometric rather than spectroscopic redshifts, affects the accuracy of derived global SFRs. Finally, we provide a publicly available catalogue of SFRs for more than 27 million galaxies extracted from the Sloan Digital Sky survey Data Release 7. The catalogue is available through the Vizier facility at the following link ftp://cdsarc.u-strasbg.fr/pub/cats/J/MNRAS/486/1377

High-frequency diffraction contribution by planar metallic–DNG metamaterial junctions

AbstractThe plane wave diffraction by a planar junction consisting of a thick metallic sheet and a lossy double-negative metamaterial slab is studied by using the Uniform Asymptotic Physical Optics approach. This approach assumes the radiation integral as a starting point and uses the physical optics surface currents as sources to be integrated. The integral is manipulated by taking advantage of useful approximations and evaluations, and re-formulated in order to apply an asymptotic procedure able to generate a closed-form approximate solution in the framework of the Uniform Geometrical Theory of Diffraction. Accordingly, advantages and drawbacks result from the application of the proposed solution. The jumps of the geometrical optics field are compensated. Implementation and handling of the computer code are facilitated by the evaluation of well-known functions and parameters. No differential/integral equations or special functions must be computed

Seeking for the Rational Basis of the Median Model: The Optimal Combination of Multi-model ENSEMBLE Results

In this paper we present an approach for the statistical analysis of multi-model ENSEMBLE results. The models considered here are operational long-range transport and dispersion models, also used for the real-time simulation of pollutant dispersion or the accidental release 5 of radioactive nuclides. We first introduce the theoretical basis (with its roots sinking into the Bayes theorem) and then apply this approach to the analysis of model results obtained during the ETEX-1 exercise. We recover some interesting results, supporting the heuristic approach called ‘median model’, originally introduced in Galmarini et al., 2004 a,b. This approach also provides a way to systematically reduce (and quantify) model uncertainties, thus supporting the decision-making process and/or regulatory-purpose activities in a very effective manner.JRC.H.4-Transport and air qualit

Seeking for the rational basis of the median model: the optimal combination of multi-model ensemble results

International audienceIn this paper we present an approach for the statistical analysis of multi-model ensemble results. The models considered here are operational long-range transport and dispersion models, also used for the real-time simulation of pollutant dispersion or the accidental release of radioactive nuclides. We first introduce the theoretical basis (with its roots sinking into the Bayes theorem) and then apply this approach to the analysis of model results obtained during the ETEX-1 exercise. We recover some interesting results, supporting the heuristic approach called "median model", originally introduced in Galmarini et al. (2004a, b). This approach also provides a way to systematically reduce (and quantify) model uncertainties, thus supporting the decision-making process and/or regulatory-purpose activities in a very effective manner

An analysis of feature relevance in the classification of astronomical transients with machine learning methods

The exploitation of present and future synoptic (multi-band and multi-epoch) surveys requires an extensive use of automatic methods for data processing and data interpretation. In this work, using data extracted from the Catalina Real Time Transient Survey (CRTS), we investigate the classification performance of some well tested methods: Random Forest, MLPQNA (Multi Layer Perceptron with Quasi Newton Algorithm) and K-Nearest Neighbors, paying special attention to the feature selection phase. In order to do so, several classification experiments were performed. Namely: identification of cataclysmic variables, separation between galactic and extra-galactic objects and identification of supernovae.Comment: Accepted by MNRAS, 11 figures, 18 page

I-21 Current therapeutic guidelines in Duchenne Muscular Dystrophy to prolong life

Duchenne's myopathy is an X-linked disease with well defined evolutionary phases, characterized by degradation of the walking function, development of evolutive scoliosis and progressive decline of the respiratory function leading patients to premature death. In 1985 Y. Rideau in France carried out a new global therapeutic strategy for treatment of lower limb deformities, scoliosis deformity and progressive restrictive syndrome. The indication for surgery at the lower limbs is made very early, at the onset of the first signs of disease. The procedures are carried out at the same time and always bilaterally; they include: (i) hip section of superficial flexors; (ii) iliotibial band resection; (iii) subcutaneous tenotomy of semitendineous and gracilis; (iv) subcutaneous lengthening of Achilles tendons. In the post-operative period, the patient begins exercises of active and passive mobility in few days and after three weeks recovers his performances; ambulation will remain almost normal for several years. A comparison of two groups of patients, the first precociously operated on the lower limbs, the other one not operated, shows better performances in the operated group. The indications for surgical treatment of Duchenne scoliosis must be made after the loss of ambulation and not too late, to avoid the concurrent respiratory restrictive syndrome makes the patient inoperable. Over ten years ago, in Poitiers, a specific instrumentation for Duchenne scoliosis was created, providing for cylindrical rods fixed by peduncular screws at the sacro-lumbar level. On the dorso-lumbar level, the rod becomes flat to allow more flexibility of the trunk. The complications observed in a group of 55 patients operated for scoliosis, consisted in 2 cases of breaking of rods and 1 superficial infection. The surgery approach in DMD has the double aim to prolong the time of the autonomous ambulation and to avoid the evolution of scoliosis, limiting the harmful effects of the scoliosis on the respiratory function. However, the surgery alone is unable to prolong the life expectancy in these patients, without treating the restrictive respiratory syndrome, first by nasal ventilation and then by elective tracheotomy, essential for the survival of the patient