Renormalization: a quasi-shuffle approach

In recent years, the usual BPHZ algorithm for renormalization in perturbative quantum field theory has been interpreted, after dimensional regularization, as a Birkhoff decomposition of characters on the Hopf algebra of Feynman graphs, with values in a Rota-Baxter algebra of amplitudes. We associate in this paper to any such algebra a universal semi-group (different in nature from the Connes-Marcolli "cosmical Galois group"). Its action on the physical amplitudes associated to Feynman graphs produces the expected operations: Bogoliubov's preparation map, extraction of divergences, renormalization. In this process a key role is played by commutative and noncommutative quasi-shuffle bialgebras whose universal properties are instrumental in encoding the renormalization process

A Computerized Syllable-Based Intervention for French-Speaking Children with Down Syndrome: What Effects on Reading Skills?

The aim of this research was to provide to eight children with Down Syndrome a syllable-processing software program that drew their attention to phonological and orthographic syllables. The children participated in a 10-hour training course (spread over 5 weeks) that used an experimental design with four assessment sessions, the first two of which were used to obtain a baseline in literacy skills. The effect of training was assessed just after training and two months later. A significant effect on decoding was observed at medium term after training. All children progressed in at least one domain, either in phonological skills, in decoding, or in word reading. Four children progressed in decoding and word reading. This study confirms the appropriateness of using phonetic approaches to reading instruction in order to stimulate learning to read in children with Down Syndrome. The syllable-based training facilitates the construction of associations between letters and syllables—the “syllabic bridge”—and could be a faster and easier way to learn letter-sound correspondences in French

The nature of the phonological processing in French dyslexic children: evidence for the phonological syllable and linguistic features' role in silent reading and speech discrimination

Abstract This study investigated the status of phonological representations in French dyslexic children (DY) compared with reading level-(RL) and chronological age-matched (CA) controls. We focused on the syllable's role and on the impact of French linguistic features. In Experiment 1, we assessed oral discrimination abilities of pairs of syllables that varied as a function of voicing, mode or place of articulation, or syllable structure. Results suggest that DY children underperform controls with a 'speed-accuracy' deficit. However, DY children exhibit some similar processing than those highlighted in controls. As in CA and RL controls, DY children have difficulties in processing two sounds that only differ in voicing, and preferentially process obstruent rather than fricative sounds, and more efficiently process CV than CCV syllables. In Experiment 2, we used a modified version of the Colé, Magnan, and Grainger's (Applied Psycholinguistics 20:507-532, 1999) paradigm. Results show that DY children underperform CA controls but outperform RL controls. However, as in CA and RL controls, data reveal that DY children are able to use phonological procedures influenced by initial syllable frequency. Thus, DY children process syllabically high-frequency syllables but phonemically process low-frequency syllables. They also exhibit lexical and syllable frequency effects. Consequently, results provide evidence that DY children performances can be accounted for by laborious phonological syllable-based procedures and also degraded phonological representations

The nature of the phonological processing in French dyslexic children: Evidence for the phonological syllable and linguistic features' role in silent reading and speech discrimination

International audienceThis study investigated the status of phonological representations in French dyslexic children (DY) compared with reading level- (RL) and chronological age-matched (CA) controls. We focused on the syllable’s role and on the impact of French linguistic features. In Experiment 1, we assessed oral discrimination abilities of pairs of syllables that varied as a function of voicing, mode or place of articulation, or syllable structure. Results suggest that DY children underperform controls with a ‘speed-accuracy’ deficit. However, DY children exhibit some similar processing than those highlighted in controls. As in CA and RL controls, DY children have difficulties in processing two sounds that only differ in voicing, and preferentially process obstruent rather than fricative sounds, and more efficiently process CV than CCV syllables. In Experiment 2, we used a modified version of the Colé, Magnan, and Grainger's (Applied Psycholinguistics 20:507–532, 1999) paradigm. Results show that DY children underperform CA controls but outperform RL controls. However, as in CA and RL controls, data reveal that DY children are able to use phonological procedures influenced by initial syllable frequency. Thus, DY children process syllabically high-frequency syllables but phonemically process low-frequency syllables. They also exhibit lexical and syllable frequency effects. Consequently, results provide evidence that DY children performances can be accounted for by laborious phonological syllable-based procedures and also degraded phonological representations

Syllable frequency effects in visual word recognition: Developmental approach in French children

International audienceThis study investigates the syllable's role in the normal reading acquisition of French children at three grade levels (1st, 3rd, and 5th), using a modified version of Colé, Magnan, and Grainger's (1999) paradigm. We focused on the effects of syllable frequency and word frequency. The results suggest that from the first to third years of reading instruction, children process high-frequency syllables as syllable units while processing low-frequency syllables as phoneme units. In fifth graders, syllable-based processing is extended to both high and low syllable frequencies, primarily due to CVC structures with high-frequency syllables. Lexical frequency does not significantly influence syllable processing. These findings reveal that the syllable is an early prelexical unit modulated initially by syllable frequency, and subsequently by grapheme-to-phoneme correspondences. High-frequency syllables did not produce inhibitory effects. Consequently, results are compatible with Levelt and Wheeldon's (1994) mental syllabary hypothesis. Implications for specific reading training and syllable based remediation are discussed

What contributes to syllable-based effects in French dyslexic children?

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Do Consonant Sonority and Status Influence Syllable-Based Segmentation Strategies in a Visual Letter Detection Task? Developmental Evidence in French Children

International audienceThis article queries whether consonant sonority (sonorant vs. obstruent) and status (coda vs. onset) within intervocalic clusters influence syllable-based segmentation strategies. We used a modified version of the illusory conjunction paradigm to test whether French beginning, intermediate, and advanced readers were sensitive to an optimal “sonorant coda–obstruent onset” sonority profile within the syllable boundaries as a cue for a syllable-based segmentation. Data showed that children used a syllable-based segmentation that improved with reading skills and age. The results are discussed to support that the visual letter detection within pseudowords primarily and early relies on acoustic-phonetic cues within the syllable boundaries, whereas the syllable effect seems to be developmentally constrained by reading skills and age