We will obtain in this paper a generic expression of any element in split g2 , the Lie algebra of the derivations of the split octonions Os over an arbitrary field. For this purpose, we will use the Zorn’s matrices. We will also compute the multiplication table of this Lie algebra. à Previous commands First of all, we define some commands that will be usefull in what follows. The first ones are...

According to Ullman's Structure-from-Motion Theorem [U79], three orthogonal projections of four points in a rigid non-planar configuration uniquely determine their structure, and the relative orientations of the three views, up to a reflection in the image plane. It is here shown that a corresponding result holds for the more general "para-perspective" case, and leads to a rapidly convergent al...

Up to now, ) formation in tRNAs was found to be catalysed by stand-alone enzymes. By computational analysis of archaeal genomes we detected putative H/ACA sRNAs, in four Sulfolobales species and in Aeropyrum pernix, that might guide )35 formation in pre-tRNA(GUA). This modification is achieved by Pus7p in eukarya. The validity of the computational predictions was verified by in vitro reconstitu...

We show that measurement of the spin-lattice ( T I ) and spin-spin ( Tz) relaxation times (or line widths) of irrotationally bound 2H nuclei in macromolecules undergoing isotropic rotational motion outside of the extreme narrowing limit (Le., for the case W o ’ 7 ~ ~ >> 1) permits determination of both the rotational correlation time ( T R ) of the macromolecule and the electric quadrupole coup...

In cases where diffraction data do not provide a clear choice between a centrosymmetric and a noncentrosymmetric space group, it is better to opt for the centrosymmetric description even though disorder may result. The disorder model implies that the crystal is a composite of two or more molecular structures that cannot be distinguished from one another. On the other hand, attempts to refine a ...

We present the implementation of Distributed Constructionism (DC) through a Participatory Design (PD) methodology for an Online Learning community. The students collaborate on the content and functionality development of an online Modern Greek language course, peer review and publish content contributions, and participate in participatory design teams. Participatory design was implemented as a ...

Algebras of design have previously been investigated for shapes composed of rectilinear geometric elements, such as lines and planes, and the properties of these algebras have been found to be beneficial for formalising designs, as well as the visual processes used by designers as they manipulate shapes in their design explorations. In this paper, an overview is presented of the application of ...