Modern JavaScript includes the SharedArrayBuffer feature, which provides access to true shared memory concurrency. SharedArrayBuffers are simple linear buffers of bytes, and the JavaScript specification defines an axiomatic relaxed memory model to describe their behaviour. While this model is heavily based on the C/C++11 model, it diverges in some key areas. JavaScript chooses to give a well-defined semantics to data-races, unlike the "undefined behaviour" of C/C++11. Moreover, the JavaScript model is mixed-size. This means that its accesses are not to discrete locations, but to (possibly overlapping) ranges of bytes.

The growth of the head and neck and its components, including that of the vocal tract, is not homothetic but appears rather as an anamorphosis. The growth of various structures presents a phenomenon of heterochrony. Another important issue in vocal tract growth is sexual dimorphism. It was first claimed that sexual dimorphism appears at puberty, but a recent study has suggested that some prepubertal differences exist. To study these two phenomena, we used longitudinal radiographic data of sixty-eight typical subjects (966 radiographs, taken from 1 month to 25 years) and twelve fetuses (anatomical sections). In this study, we analyzed the growth curves and growth types of the hard and soft palate, the pharyngeal cavity and the estimated length of the whole vocal tract using non-linear mixed-effect models, in order to take advantage of our unique longitudinal dataset. Results indicate that most of the structures follow a neural/somatic growth type, while the pharyngeal cavity follows a more somatic growth type. As concerns sexual dimor-phism, no prepubertal differences were found, suggesting that the sexual dimorphism is likely to begin at puberty. These results have implications for the acoustics of speech production during development and should lead to improvements in vocal tract growth modeling.

This study investigates speech motor control in 4-year-old Canadian French children in comparison with adults.It focuses on measures of token-to-token variability in the production of isolated vowels and on anticipatory extrasyllabic coarticulation within V 1 -C-V 2 sequences.Acoustic and ultrasound articulatory data were recorded.Acoustic data from 20 children and 10 adults have been analyzed.Thus far, ultrasound data have been analyzed from a subset of these participants: 6 children and 2 adults.In agreement with former studies, token-to-token variability was greater in children than in adults.Strong anticipation of V 2 in V 1 was found in all adults, but not in children.Most of the children showed no anticipation at all and some of them showed a small amount of anticipation along the antero-posterior dimension only, manifested in the acoustic F2 dimension.These results are interpreted as evidence for the immaturity of children's speech motor control from two perspectives: insufficiently stable motor control patterns for vowel production, and a lack of effectiveness in anticipating forthcoming gestures.In line with theories of optimal motor control, anticipatory coarticulation is assumed to be based on the use of internal models of the speech apparatus and the increasing maturation of these representations as speech develops.

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