RBF neural net based classifier for the AIRIX accelerator fault diagnosis

The AIRIX facility is a high current linear accelerator (2-3.5kA) used for flash-radiography at the CEA of Moronvilliers France. The general background of this study is the diagnosis and the predictive maintenance of AIRIX. We will present a tool for fault diagnosis and monitoring based on pattern recognition using artificial neural network. Parameters extracted from the signals recorded on each shot are used to define a vector to be classified. The principal component analysis permits us to select the most pertinent information and reduce the redundancy. A three layer Radial Basis Function (RBF) neural network is used to classify the states of the accelerator. We initialize the network by applying an unsupervised fuzzy technique to the training base. This allows us to determine the number of clusters and real classes, which define the number of cells on the hidden and output layers of the network. The weights between the hidden and the output layers, realising the non-convex union of the clusters, are determined by a least square method. Membership and ambiguity rejection enable the network to learn unknown failures, and to monitor accelerator operations to predict future failures. We will present the first results obtained on the injector.Comment: 3 pages, 4 figures, LINAC'2000 conferenc

GPS Precision Timing at CERN

For the past decade, the Global Positioning System (GPS) has been used to provide precise time, frequency and position co-ordinates world-wide. Recently, equipment has become available specialising in providing extremely accurate timing information, referenced to Universal Time Co-ordinates (UTC). This feature has been used at CERN to provide time of day information for systems that have been installed in the Proton Synchrotron (PS), Super Proton Synchrotron (SPS) and the Large Electron Positron (LEP) machines. The different systems are described as well as the planned developments, particularly with respect to optical transmission and the Inter-Range Instrumentation Group IRIG-B standard, for future use in the Large Hadron Collider (LHC)

Degradation of Plasticised Poly(lactide) Composites with Nanofibrillated Cellulose in Different Hydrothermal Environments

In this study, bionanocomposite films based on poly(lactide) (PLA) plasticised with poly(ethylene glycol) (PEG) (7.5 wt%) and reinforced with various contents of nanofibrillated cellulose (NFC) (1, 3, 5 wt%) were prepared. The hydrothermal degradation was investigated through immersion in several aqueous environments at temperatures of 8, 23, 58, and 70 °C as a function of time (7, 15, 30, 60, 90 days). The effect of water immersion on the physicochemical properties of the materials was assessed by monitoring the changes in the morphology, thermo-oxidative stability, thermal properties, and molar mass through field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and gel permeation chromatography (GPC). The hydrothermal degradation behaviour was not critically affected regardless of the nanofibrillated cellulose content. All the materials revealed certain integrity towards water immersion and hydrolysis effects at low temperatures (8 and 23 °C). The low hydrothermal degradation may be an advantage for using these PLA biocomposites in contact with water at ambient temperatures and limited exposure times. On the other hand, immersion in water at higher temperatures above the glass transition (58 and 70 °C), leads to a drastic deterioration of the properties of these PLA-based materials, in particular to the reduction of the molar mass and the disintegration into small pieces. This hydrothermal degradation behaviour can be considered a feasible option for the waste management of PLA/PEG/NFC bionanocomposites by deposition in hot aqueous environments

Structure–Properties Relationship of Reprocessed Bionanocomposites of Plasticized Polylactide Reinforced with Nanofibrillated Cellulose

Bionanocomposites of polylactide (PLA), plasticized with poly(ethylene glycol) (PEG) (7.5 wt%, 400 and 1500 g/mol) and reinforced with nanofibrillated cellulose (NFC) (1, 3, and 5 wt%) were sequentially compounded, and injection and compression molded. All of the stages caused structural and morphological consequences, more relevant in the plasticized PLA, especially with low molar PEG. Small percentages of NFC (1 and 3 wt%) acted as crystalline nucleating agents and improved thermo-oxidative stability. Given the substantial degradation caused by (re)processing, a downgrading validation strategy was applied, assessing the mechanical and water contact performance during fictional first and second service life applications. After the first processing, PEG increased the ductility and reduced the strength and elastic modulus, while NFC buffered the fall in stiffness and increased rigidity compared to their PLA-PEG counterparts. Once reprocessed, PEG increased the water affinity of the blend, especially for low molar mass PEG. Low percentages of NFC (1 and 3 wt%) modulated water diffusivity and permeability, regardless of the water temperature. Overall, although reprocessing caused significant degradation, the mechanical valorization possibilities of these green bionanocomposites were proven, and are pointed out as sustainable candidates for food packaging or agricultural applications where modulated mechanical or water contact behaviors are required

Functional food science and defence against reactive oxidative species

This paper assesses critically the science base that underpins the argument that oxidative damage is a significant causative factor in the development of human diseases and that antioxidants are capable of preventing or ameliorating these disease processes. The assessment has been carried out under a number of headings, and some recommendations for future research are made based on the present day knowledge bas

LA IGUALACIÓN DE LA MUESTRA COMO SELECCIÓN DE LOS ESTÍMULOS DE SEGUNDO ORDEN: EFECTOS DE DOS PROCEDIMIENTOS

Participaron voluntariamente 22 estudiantes universitarios de ambos sexos en un estudio para evaluar el efecto de discriminar los estímulos de segundo orden en la adquisición y transferencia de una discriminación condicional. Los participantes fueron distribuidos en seis grupos, expuestos a distintos procedimientos y secuencia de procedimientos. Se emplearon tres procedimientos de igualación de la muestra de segundo orden: por selección del estímulo de comparación, por selección de estímulos de segundo orden, y por selección matricial de todos los estímulos de segundo orden y de comparación. Los resultados de este experimento muestran que la presentación inicial del procedimiento de igualación matricial produjo ejecuciones correctas al 100% desde la primera sesión. Se examinan estos resultados en términos de los efectos de la comparación forzada de los estímulos sobre la facilitación de una discriminación verbal del criterio de igualación.Palabras clave: igualación de la muestra, criterio de igualación, estímulos de segundo orden, reconocimiento verbal, adultos jóvenes

Newborn screening for medium-chain acyl-CoA dehydrogenase deficiency: regional experience and high incidence of carnitine deficiency

Background Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is the most common inherited defect in the mitochondrial fatty acid oxidation pathway, resulting in significant morbidity and mortality in undiagnosed patients. Newborn screening (NBS) has considerably improved MCADD outcome, but the risk of complication remains in some patients. The aim of this study was to evaluate the relationship between genotype, biochemical parameters and clinical data at diagnosis and during follow-up, in order to optimize monitoring of these patients. Methods We carried out a multicenter study in southwest Europe, of MCADD patients detected by NBS. Evaluated NBS data included free carnitine (C0) and the acylcarnitines C8, C10, C10:1 together with C8/C2 and C8/C10 ratios, clinical presentation parameters and genotype, in 45 patients. Follow-up data included C0 levels, duration of carnitine supplementation and occurrence of metabolic crises. Results C8/C2 ratio and C8 were the most accurate biomarkers of MCADD in NBS. We found a high number of patients homozygous for the prevalent c.985A > G mutation (75%). Moreover, in these patients C8, C8/C10 and C8/C2 were higher than in patients with other genotypes, while median value of C0 was significantly lower (23 μmol/L vs 36 μmol/L). The average follow-up period was 43 months. To keep carnitine levels within the normal range, carnitine supplementation was required in 82% of patients, and for a longer period in patients homozygotes for the c.985A>G mutation than in patients with other genotypes (average 31 vs 18 months). Even with treatment, median C0 levels remained lower in homozygous patients than in those with other genotypes (14 μmol/L vs 22 μmol/L). Two patients died and another three suffered a metabolic crisis, all of whom were homozygous for the c.985 A>G mutation. Conclusions Our data show a direct association between homozygosity for c.985A>G and lower carnitine values at diagnosis, and a higher dose of carnitine supplementation for maintenance within the normal range. This study contributes to a better understanding of the relationship between genotype and phenotype in newborn patients with MCADD detected through screening which could be useful in improving follow-up strategies and clinical outcome

New records and detailed distribution and abundance of selected arthropod species collected between 1999 and 2011 in Azorean native forests

[Background] In this contribution we present detailed distribution and abundance data for arthropod species identified during the BALA ¿ Biodiversity of Arthropods from the Laurisilva of the Azores (1999-2004) and BALA2 projects (2010-2011) from 18 native forest fragments in seven of the nine Azorean islands (all excluding Graciosa and Corvo islands, which have no native forest left).[New information] Of the total 286 species identified, 81% were captured between 1999 and 2000, a period during which only 39% of all the samples were collected. On average, arthropod richness for each island increased by 10% during the time frame of these projects. The classes Arachnida, Chilopoda and Diplopoda represent the most remarkable cases of new island records, with more than 30% of the records being novelties. This study stresses the need to expand the approaches applied in these projects to other habitats in the Azores, and more importantly to other less surveyed taxonomic groups (e.g. Diptera and Hymenoptera). These steps are fundamental for getting a more accurate assessment of biodiversity in the archipelago.AMCS was supported by a Marie Curie Intra-European Fellowship (IEF 331623 ‘COMMSTRUCT’) and by a Juan de la Cierva Fellowship (IJCI-2014-19502) funded by the Spanish ‘Ministerio de Economía y Competitividad’.Peer Reviewe