RoboMusic with modular playware

Based on the concepts of RoboMusic and modular playware, we developed a system composed of modular playware devices which allow any user to perform music in a simple, interactive manner. The key features exploited in the modular playware approach are modularity, flexibility, construction, immediate feedback to stimulate engagement, creative exploration of play activities, and in some cases activity design by end-users (e.g., DJs). We exemplify the approach with the development of 11 rock genres and 6 pop music pieces for modular I-BLOCKS, which are exhibited and in daily use at the Rock Me exhibition, and have been used at several international music events in Japan and the USA. A key finding is that professional music design is essential for the development of primitives in a musical behavior-based system, and this professional esthetics is necessary to engage the users in the activity of assembling and coordinating these “professional” musical primitives. This article describes, explores, and discusses this concept.     

A Study of the Evaluator Effect in Usability Testing

ABSTRACT

The evaluator effect names the observation that usability evaluators in similar conditions identify substantially different sets of usability problems. Yet little is known about the factors involved in the evaluator effect. We present a study of 50 novice evaluators' usability tests and subsequent comparisons, in teams and individually, of the resulting usability problems. The same problems were analyzed independently by 10 human–computer interaction experts. The study shows an agreement between evaluators of about 40%, indicating a substantial evaluator effect. Team matching of problems following the individual matching appears to improve the agreement, and evaluators express greater satisfaction with the teams' matchings. The matchings of individuals, teams, and independent experts show evaluator effects of similar sizes; yet individuals, teams, and independent experts fundamentally disagree about which problems are similar. Previous claims in the literature about the evaluator effect are challenged by the large variability in the matching of usability problems; we identify matching as a key determinant of the evaluator effect. An alternative view of usability problems and evaluator agreement is proposed in which matching is seen as an activity that helps to make sense of usability problems and where the existence of a correct matching is not assumed.     

Conversion of tyrosine phenol-lyase to dicarboxylic amino acid beta-lyase, an enzyme not found in nature

Tyrosine phenol-lyase (TPL), which catalyzes the beta-elimination reaction of L-tyrosine, and aspartate aminotransferase (AspAT), which catalyzes the reversible transfer of an amino group from dicarboxylic amino acids to oxo acids, both belong to the alpha-family of vitamin B6-dependent enzymes. To switch the substrate specificity of TPL from L-tyrosine to dicarboxylic amino acids, two amino acid residues of AspAT, thought to be important for the recognition of dicarboxylic substrates, were grafted into the active site of TPL. Homology modeling and molecular dynamics identified Val-283 in TPL to match Arg-292 in AspAT, which binds the distal carboxylate group of substrates and is conserved among all known AspATs. Arg-100 in TPL was found to correspond to Thr-109 in AspAT, which interacts with the phosphate group of the coenzyme. The double mutation R100T/V283R of TPL increased the beta-elimination activity toward dicarboxylic amino acids at least 10(4)-fold. Dicarboxylic amino acids (L-aspartate, L-glutamate, and L-2-aminoadipate) were degraded to pyruvate, ammonia, and the respective monocarboxylic acids, e.g. formate in the case of L-aspartate. The activity toward L-aspartate (kcat = 0.21 s-1) was two times higher than that toward L-tyrosine. beta-Elimination and transamination as a minor side reaction (kcat = 0.001 s-1) were the only reactions observed. Thus, TPL R100T/V283R accepts dicarboxylic amino acids as substrates without significant change in its reaction specificity. Dicarboxylic amino acid beta-lyase is an enzyme not found in nature.     

Potential effects of broadband wireline telecommunications on the HF spectrum

Power line telecommunications and various forms of digital subscriber line transmissions are recent and rapidly evolving technologies using the existing electricity power or telephone lines for data transmission at rates higher than 1 Mb/s. As these lines were not designed for transmission of high data rates, they produce noiselike interferences in the HF range. The intensity depends on the electrical characteristics of the lines (balance, match, screening) as well as on the density and area coverage of these new systems. Exact calculations are impossible at this time because of missing models for the new wirebound communication systems with respect to emission of radio noise in the HF band. Early measurements and estimations showed that radio noise from PLT and xDSL has the potential to cause problems for military HF radio communications and communication intelligence. A Research Task Group under NATO was assigned to study the issue and determine possible solutions. Briefly, the findings of the RTG do indicate that PLT emissions have the potential to cause appreciable degradation in the exploitation of the HF spectrum by military users.     

A generalization of the Friedlander Algorithm balancing of national accounts matrices

Owing to stochastic and systematic errors in test samples, the first estimates of national accounts items rarely satisfy all the well known definitional identities. Stone, Champernowne and Meade presented the initial argument for GLS balancing of such accounting matrices in 1942. The GLS principles were, however, rarely used in practical empirical work until Byron facilitated the computational process by applying the Conjugate Gradient Algorithm in 1978. This paper shows how a slight adjustment of another numerical process, the Friedlander Algorithm, generates an efficient and conceptually simple approach to the computation of a GLS-balanced set of accounts.     

Fast calibration of high-order adaptive optics systems

We present a new method of calibrating adaptive optics systems that greatly reduces the required calibration time or, equivalently, improves the signal-to-noise ratio. The method uses an optimized actuation scheme with Hadamard patterns and does not scale with the number of actuators for a given noise level in the wavefront sensor channels. It is therefore highly desirable for high-order systems and/or adaptive secondary systems on a telescope without a Gregorian focal plane. In the latter case, the measurement noise is increased by the effects of the turbulent atmosphere when one is calibrating on a natural guide star.     

Virtual trackballs revisited

Rotation of three-dimensional objects by a two-dimensional mouse is a typical task in computer-aided design, operation simulations, and desktop virtual reality. The most commonly used rotation technique is a virtual trackball surrounding the object and operated by the mouse pointer. We review and provide a mathematical foundation for virtual trackballs. The first, but still popular, virtual trackball was described by Chen et al. (1998). We show that the virtual trackball by Chen et al. does not rotate the object along the intended great circular arc on the virtual trackball and we give a correction. Another popular virtual trackball is Shoemake's quaternion implementation (1992), which we show to be a special case of the virtual trackball by Chen et al.. Shoemake extends the scope of the virtual trackball to the full screen. Unfortunately, Shoemake's virtual trackball is inhomogeneous and discontinuous with consequences for usability. Finally, we review Bell's virtual trackball (1998) and discuss studies of the usability of virtual trackballs.     

Risperidone in the treatment of schizophrenia: results of a study of patients from Germany, Austria, and Switzerland

Wound healing is a complex series of highly interdependent and overlapping stages involving a number of cellular processes. Macrophages are pivotal to the healing process, as director cells, but also functioning as phagocytes and debridement agents in addition to producing chemoattractants and growth factors which attract cells necessary for repair and control of wound healing processes. A number of other factors influence wound healing, such as oxygen, the immune system, and corticosteroids.