Real-time dynamic articulations in the 2-D waveguide mesh vocal tract model

Time domain articulatory vocal tract modeling in one-dimensional (1-D) is well established. Previous studies into two-dimensional (2-D) simulation of wave propagation in the vocal tract have shown it to present accurate static vowel synthesis. However, little has been done to demonstrate how such a model might accommodate the dynamic tract shape changes necessary in modeling speech. Two methods of applying the area function to the 2-D digital waveguide mesh vocal tract model are presented here. First, a method based on mapping the cross-sectional area onto the number of waveguides across the mesh, termed a widthwise mapping approach is detailed. Discontinuity problems associated with the dynamic manipulation of the model are highlighted. Second, a new method is examined that uses a static-shaped rectangular mesh with the area function translated into an impedance map which is then applied to each waveguide. Two approaches for constructing such a map are demonstrated; one using a linear impedance increase to model a constriction to the tract and another using a raised cosine function. Recommendations are made towards the use of the cosine method as it allows for a wider central propagational channel. It is also shown that this impedance mapping approach allows for stable dynamic shape changes and also permits a reduction in sampling frequency leading to real-time interaction with the model

Mineral Trioxide Aggregate Material Use in Endodontic Treatment: A Review of the Literature

Objective The purpose of this paper was to review the composition, properties, biocompatibility, and the clinical results involving the use of mineral trioxide aggregate (MTA) materials in endodontic treatment. Methods Electronic search of scientific papers from January 1990 to August 2006 was accomplished using PubMed and Scopus search engines (search terms: MTA, GMTA, WMTA, mineral AND trioxide AND aggregate). Results Selected exclusion criteria resulted in 156 citations from the scientific, peer-reviewed dental literature. MTA materials are derived from a Portland cement parent compound and have been demonstrated to be biocompatible endodontic repair materials, with its biocompatible nature strongly suggested by its ability to form hydroxyappatite when exposed to physiologic solutions. With some exceptions, MTA materials provide better microleakage protection than traditional endodontic repair materials using dye, fluid filtration, and bacterial penetration leakage models. In both animal and human studies, MTA materials have been shown to have excellent potential as pulp-capping and pulpotomy medicaments but studies with long-term follow-up are limited. Preliminary studies suggested a favorable MTA material use as apical and furcation restorative materials as well as medicaments for apexogenesis and apexification treatments; however, long-term clinical studies are needed in these areas. Conclusion MTA materials have been shown to have a biocompatible nature and have excellent potential in endodontic use. MTA materials are a refined Portland cement material and the substitution of Portland cement for MTA products is presently discouraged. Existing human studies involving MTA materials are very promising, however, insufficient randomized, double-blind clinical studies of sufficient duration exist involving MTA for all of its clinical indications. Further clinical studies are needed in these areas

The Therapeutic Bond Scales: Psychometric Characteristics and Relationship to Treatment Effectiveness

The Therapeutic Bond Scales assess the quality of the therapeutic relationship from the patient\u27s perspective. The therapeutic bond is composed of 3 aspects: working alliance, empathic resonance, and mutual affirmation. Scales were developed to measure these aspects and the therapeutic bond as a whole. The correlations between these scales and 2 measures of outcome (session quality assessed by the patient and termination outcome evaluated by nonparticipant raters) were examined. All scales were significantly correlated with session quality. Therapeutic bond was significantly correlated with termination outcome in both a linear and a curvilinear fashion, suggesting that, at least in the initial phase of therapy, the therapeutic bond can be too high as well as too low

The Need for a Supranational Organization in Foreign Investment

While the World Trade Organization (“WTO”) does not regulate the field of foreign investment, the WTO has tried to negotiate multilateral rules on foreign investment in the past, and there are other current international agreements that contain investment provisions designed to regulate foreign investment. Even though the previous multilateral investment agreement negotiations did not come to fruition, some scholars still believe there are several practical reasons for the WTO to regulate investment. Most significantly, trade and investment are strongly linked in our globalizing world and both are complements one another, with an increase in one corresponding to an increase in the other. But history has divided these two pillars of our global economy, as trade is regulated through a multilateral regime under the WTO while investment is instead regulated by thousands of international investment agreements (IIAs), primarily bilateral investment treaties (“BIT”), and decentralized arbitral disputes. This Article proposes the creation of a separate supranational investment organization to serve as a multilateral regulatory body on investment and a forum for investment negotiations while still maintaining the economic link between investment and trade—namely, the institution of a World Investment Organization. This Article will start by comparing trade and foreign investment to better understand the arguments that the WTO should in theory regulate foreign investment. Trade and investment are strongly linked, but there are still distinct differences between the two international legal fields. Additionally, this Article will focus on the compelling reasons for a multilateral regime on foreign investment and why a de jure rather than a de facto multilateral investment agreement is needed. This Article will also argue for the necessity of a WIO, particularly focusing on the past attempts of the WTO to regulate foreign investment. Finally, it will focus on the creation and structure of the WIO and drawbacks to this proposal, focusing particularly on the legitimacy challenges to the organization and the hold-out problem confronting its establishment