32 research outputs found

    Variables influencing executive functioning in preschool hearing-impaired children implanted within 24 months of age: an observational cohort study

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    Executive Functions (EFs) are fundamental to every aspect of life. The present study was implemented to evaluate factors influencing their development in a group of preschools orally educated profoundly deaf children of hearing parents, who received CI within two years of age. Methods Twenty-five preschool CI children were tested using the Battery for Assessment of Executive Functions (BAFE) to assess their flexibility, inhibition and non-verbal visuo-spatial working memory skills. The percentage of children performing in normal range was reported for each of the EF subtests. Mann-Whitney and Kruskal-Wallis were performed to assess differences between gender, listening mode and degree of parents’ education subgroups. The Spearman Rank Correlation Coefficient was calculated to investigate the relationship between EF scores audiological and linguistic variables. Results Percentages ranging from 76% to 92% of the children reached adequate EF scores at BAFE. Significant relations (p<0.05) were found between EFs and early intervention, listening and linguistic skills. Further, CI children from families with higher education level performed better at the response shifting, inhibitory control and attention flexibility tasks. Economic income correlated significantly with flexibility and inhibitory skills. Females performed better than males only in the attention flexibility task. Conclusions The present study is one of the first to focus attention on the development of EFs in preschool CI children, providing an initial understanding of the characteristics of EFs at the age when these skills emerge. Clinical practice must pay increasing attention to these aspects which are becoming the new emerging challenge of rehabilitation programs

    Current drive at plasma densities required for thermonuclear reactors

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    Progress in thermonuclear fusion energy research based on deuterium plasmas magnetically confined in toroidal tokamak devices requires the development of efficient current drive methods. Previous experiments have shown that plasma current can be driven effectively by externally launched radio frequency power coupled to lower hybrid plasma waves. However, at the high plasma densities required for fusion power plants, the coupled radio frequency power does not penetrate into the plasma core, possibly because of strong wave interactions with the plasma edge. Here we show experiments performed on FTU (Frascati Tokamak Upgrade) based on theoretical predictions that nonlinear interactions diminish when the peripheral plasma electron temperature is high, allowing significant wave penetration at high density. The results show that the coupled radio frequency power can penetrate into high-density plasmas due to weaker plasma edge effects, thus extending the effective range of lower hybrid current drive towards the domain relevant for fusion reactors

    Périgord black truffle genome uncovers evolutionary origins and mechanisms of symbiosis

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    LetterInternational audienceThe Périgord black truffle (Tuber melanosporumTuber\ melanosporum Vittad.) and the Piedmont white truffle dominate today's truffle market. The hypogeous fruiting body of T. melanosporumT.\ melanosporum is a gastronomic delicacy produced by an ectomycorrhizal symbiont endemic to calcareous soils in southern Europe. The worldwide demand for this truffle has fuelled intense efforts at cultivation. Identification of processes that condition and trigger fruit body and symbiosis formation, ultimately leading to efficient crop production, will be facilitated by a thorough analysis of truffle genomic traits. In the ectomycorrhizal Laccaria bicolorLaccaria\ bicolor, the expansion of gene families may have acted as a 'symbiosis toolbox'. This feature may however reflect evolution of this particular taxon and not a general trait shared by all ectomycorrhizal species. To get a better understanding of the biology and evolution of the ectomycorrhizal symbiosis, we report here the sequence of the haploid genome of T. melanosporumT.\ melanosporum, which at ∼\sim125 megabases is the largest and most complex fungal genome sequenced so far. This expansion results from a proliferation of transposable elements accounting for ∼\sim58% of the genome. In contrast, this genome only contains ∼\sim7,500 protein-coding genes with very rare multigene families. It lacks large sets of carbohydrate cleaving enzymes, but a few of them involved in degradation of plant cell walls are induced in symbiotic tissues. The latter feature and the upregulation of genes encoding for lipases and multicopper oxidases suggest that T. melanosporumT.\ melanosporum degrades its host cell walls during colonization. Symbiosis induces an increased expression of carbohydrate and amino acid transporters in both L. bicolorL.\ bicolor and T. melanosporumT.\ melanosporum, but the comparison of genomic traits in the two ectomycorrhizal fungi showed that genetic predispositions for symbiosis −-'the symbiosis toolbox'−- evolved along different ways in ascomycetes and basidiomycete

    Lightning protection of home automation systems

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    Lightning discharges are able to damage electric and electronic devices that usually have a low protection level and are influenced also by current or voltage pulses with a relatively low energy, such as those induced by lightning currents. Home automation systems contain electronic parts and hence are more vulnerable than normal electric systems. The risk of damage can be assessed by using the procedure described in the standard series IEC 62305. Then, protection measures can be characterized, if necessary, in order to reduce the value of the economic loss to an acceptable level

    Probabilistic method for reliability assessment of metal oxide varistors under lightning stress

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    Surge protective devices are used to limit the maximum voltage on protected circuits. In the last decade, metal oxide varistors (MOVs) have been the most used protective devices. Since many of the outages experienced on sensitive circuits are due to overvoltages originated by the effects of direct and nearby lightning flashes, it is important to evaluate the reliability of such protective devices under lightning stress. Actually, MOVs are affected by ageing, essentially due to the number and amplitude of stresses, and also other factors such as overheating, pollution and humidity. The aim of this paper is to present a method, based on probabilistic arguments, to evaluate the ageing process of MOVs The expected fife, so obtained can be used to decide when the MOV must be changed before its failure occurs (reliability assessment), since the main standards do not give definitive indications about such features. The estimated expected fife can be used in the design of logistic/maintenance procedures
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