Cognitive and behavioural therapy of voices for with patients intellectual disability: Two case reports

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From upright to upside-down presentation: A spatio-temporal ERP study of the parametric effect of rotation on face and house processing

<p>Abstract</p> <p>Background</p> <p>While there is a general agreement that picture-plane inversion is more detrimental to face processing than to other seemingly complex visual objects, the origin of this effect is still largely debatable. Here, we address the question of whether face inversion reflects a quantitative or a qualitative change in processing mode by investigating the pattern of event-related potential (ERP) response changes with picture plane rotation of face and house pictures. Thorough analyses of topographical (Scalp Current Density maps, SCD) and dipole source modeling were also conducted.</p> <p>Results</p> <p>We find that whilst stimulus orientation affected in a similar fashion participants' response latencies to make face and house decisions, only the ERPs in the N170 latency range were modulated by picture plane rotation of faces. The pattern of N170 amplitude and latency enhancement to misrotated faces displayed a curvilinear shape with an almost linear increase for rotations from 0° to 90° and a dip at 112.5° up to 180° rotations. A similar discontinuity function was also described for SCD occipito-temporal and temporal current foci with no topographic distribution changes, suggesting that upright and misrotated faces activated similar brain sources. This was confirmed by dipole source analyses showing the involvement of bilateral sources in the fusiform and middle occipital gyri, the activity of which was differentially affected by face rotation.</p> <p>Conclusion</p> <p>Our N170 findings provide support for both the quantitative and qualitative accounts for face rotation effects. Although the qualitative explanation predicted the curvilinear shape of N170 modulations by face misrotations, topographical and source modeling findings suggest that the same brain regions, and thus the same mechanisms, are probably at work when processing upright and rotated faces. Taken collectively, our results indicate that the same processing mechanisms may be involved across the whole range of face orientations, but would operate in a non-linear fashion. Finally, the response tuning of the N170 to rotated faces extends previous reports and further demonstrates that face inversion affects perceptual analyses of faces, which is reflected within the time range of the N170 component.</p

Résistance à la corrosion et biocompatibilité des fils orthodontiques

Différents matériaux sont actuellement utilisés pour réaliser des fils orthodontiques. Cet article propose une synthèse sur leur résistance à la corrosion et leur biocompatibilité. Dans une première partie, après quelques rappels succincts sur les mécanismes de corrosion, les auteurs développent les caractéristiques électrochimiques des trois grandes familles d'alliages utilisés en orthodontie. Ils étudient plus particulièrement la résistance à la corrosion des alliages en nickel-titane et, grâce à leurs résultats expérimentaux, ils démontrent que ce type d'alliages est sujet à la corrosion en milieu acide et fluoré. Dans une seconde partie, les auteurs abordent la biocompatibilité de ces alliages. Tout d'abord, ils évoquent la toxicité du nickel et l'allergie que peut engendrer cet élément. Puis, la biocompatibilité des alliages utilisés en orthodontie est évaluée d'après des études sur le relargage d'éléments métalliques à partir des fils orhodontiques et d'après les études de compatibilité cellulaire au contact de ces fils. L'état de surface des matériaux a une très grande influence sur leur biocompatibilité. Au total, bien que la majorité des travaux conduits jusqu'à ce jour montre un comportement biologique satisfaisant des fils orthodontiques, il faut reconnaître qu'il persiste encore de nombreuses questions à ce sujet : les performances in vivo à long terme de l'ensemble de ces matériaux ne sont pas encore exactement évaluées et, compte tenu de l'état actuel de nos connaissances. Il paraît, ainsi, indispensable d'entreprendre de nouvelles études

Influence of autoclave sterilization on the surface parameters and mechanical properties of six orthodontic wires

International audienceOrthodontic wires are frequently packaged in individual sealed bags in order to avoid cross-contamination. The instructions on the wrapper generally advise autoclave sterilization of the package and its contents if additional protection is desired. However, sterilization can modify the surface parameters and the mechanical properties of many types of material. The aim of this research was to determine the influence of one of the most widely used sterilization processes, autoclaving (18 minutes at 134degreesC, as recommended by the French Ministry of Health), on the surface parameters and mechanical properties of six wires currently used in orthodontics (one stainless steel alloy: Tru-Chrome(R) RMO; two nickel-titanium shape memory alloys: Neo Sentalloy(R) and Neo Sentalloy with Ionguard(R) GAC; and three titanium-molybdenum alloys: TMA(R) and Low Friction TMA(R) Ormco and Resolve(R) GAC). The alloys were analysed on receipt and after sterilization, using surface structure observation techniques, including optical, scanning electron and atomic force microscopy and profilometry. The mechanical properties were assessed by three-point bending tests. The results showed that autoclave sterilization had no adverse effects on the surface parameters or on the selected mechanical properties. This supports the possibility for practitioners to systematically sterilize wires before placing them in the oral environment