The discovery of the signal peptides that direct proteins to localize at the nucleolus is described here. The nucleolar targeting signal termed the NOS consists of clustered basic amino acids organized such that a portion also functions as the nuclear transporting signal. Although a NOS has been identified within the regulatory genes of human retroviruses, HTLV‐I and HIV‐I, signals of similar function in cellular proteins – such as heat shock proteins – may be induced through the configurational change of protein (...) structure by heat or stress. (shrink)

Specular reflections and refractive distortions are complex image properties of solid transparent objects, but despite this complexity, we readily perceive the 3D shapes of these objects. We have found in past work that relevant sources of scene complexity have differential effects on 3D shape perception, with specular reflections increasing perceived thickness, and refractive distortions decreasing perceived thickness. In an object with both elements, such as glass, the two optical properties may complement each other to support reliable perception of 3D shape. (...) We investigated the relative dominance of specular reflection and refractive distortions in the perception of shape. Surprisingly, the ratio of specular reflection to refractive component was almost equal to that of ordinary glass and ice, which promote correct percepts of 3D shape. The results were also explained by the variance in local RMS contrast in stimulus images but may depend on overall luminance and contrast of the surrounding light field. (shrink)

Ainu artists were invited to make “replicas” of traditional Ainu arts held in an important museum collection and describe their choices, process and results. The resulting Ainu aesthetics challenges—and changes—our understanding of aesthetics and the philosophy of art, on four levels: descriptive aesthetics, categorical aesthetics (the categories through which the Ainu understand aesthetic value), implications of these aesthetics for a variety of human activities such as museum practice and daily life, and the implications of the first three for our broader (...) understanding of aesthetics and the philosophy of art. Preliminary analysis of Ainu aesthetics suggests it is interested in it not only as the creation and appreciation of pleasure, but also as the creation and appreciation of meaning, of sacrality, of community, and of knowledge. These latter become especially important given the threats to Ainu culture presented first by incorporation into the Japanese polity and culture and then by modernization and commercialization. Ainu works of art, therefore, carry special significance as means of conveying to current and future generations not only the aesthetic experiences of the past, but their sacred relations, sense of community, and knowledge. This suggests new roles for arts and for museums as they strive to present the works in their full physicality to contemporary audiences, especially those of Ainu artists. (shrink)

This contribution explores the reciprocal links between the organisational transformation of Western European Green parties and the access of some of these parties to national government participation. On the one hand, a series of hypotheses with regard to the possible link between prior organisational adaptation and eventual access to governmental participation are examined. On the other hand, the opposite question is addressed : that of the potential impact of governmental participation on further organisational adaptation. Following both a qualitative and Qualitative (...) Comparative Analysis, one does ultimately identify a link between prior organisational adaptation and eventual access to government, but a much more indirect and contrasted link between governmental participation and further organisational adaptation. (shrink)

The use of the axial vector representing a three-dimensional rotation makes the rotation representation much more compact by extending the trigonometric functions to vectorial arguments. Similarly, the pure Lorentz transformations are compactly treated by generalizing a scalar rapidity to a vector quantity in spatial three-dimensional cases and extending hyperbolic functions to vectorial arguments. A calculation of the Wigner rotation simplified by using the extended functions illustrates the fact that the rapidity vector space obeys hyperbolic geometry. New representations bring a Lorentz-invariant (...) fundamental equation of motion corresponding to the Galilei-invariant equation of Newtonian mechanics. (shrink)

Complex systems can be characterized by classes of equivalency of their elements defined according to system specific rules. We propose a generalized preferential attachment model to describe the class size distribution. The model postulates preferential growth of the existing classes and the steady influx of new classes. According to the model, the distribution changes from a pure exponential form for zero influx of new classes to a power law with an exponential cut-off form when the influx of new classes is (...) substantial. Predictions of the model are tested through the analysis of a unique industrial database, which covers both elementary units (products) and classes (markets, firms) in a given industry (pharmaceuticals), covering the entire size distribution. The model's predictions are in good agreement with the data. The paper sheds light on the emergence of the exponent tau approximately 2 observed as a universal feature of many biological, social and economic problems. (shrink)