Matrix Factorizations and Homological Mirror Symmetry on the Torus

We consider matrix factorizations and homological mirror symmetry on the torus T^2 using a Landau-Ginzburg description. We identify the basic matrix factorizations of the Landau-Ginzburg superpotential and compute the full spectrum, taking into account the explicit dependence on bulk and boundary moduli. We verify homological mirror symmetry by comparing three-point functions in the A-model and the B-model.Comment: 41 pages, 9 figures, v2: reference added, minor corrections and clarifications, version published in JHE

Grain Surface Models and Data for Astrochemistry

AbstractThe cross-disciplinary field of astrochemistry exists to understand the formation, destruction, and survival of molecules in astrophysical environments. Molecules in space are synthesized via a large variety of gas-phase reactions, and reactions on dust-grain surfaces, where the surface acts as a catalyst. A broad consensus has been reached in the astrochemistry community on how to suitably treat gas-phase processes in models, and also on how to present the necessary reaction data in databases; however, no such consensus has yet been reached for grain-surface processes. A team of ∼25 experts covering observational, laboratory and theoretical (astro)chemistry met in summer of 2014 at the Lorentz Center in Leiden with the aim to provide solutions for this problem and to review the current state-of-the-art of grain surface models, both in terms of technical implementation into models as well as the most up-to-date information available from experiments and chemical computations. This review builds on the results of this workshop and gives an outlook for future directions

Polynomial modeling of child and adult intonation in German spontaneous speech

de Ruiter L. Polynomial modeling of child and adult intonation in German spontaneous speech. Language and Speech. 2011;54(2):199-223.In a data set of 291 spontaneous utterances from German 5-year-olds, 7-year-olds and adults, nuclear pitch contours were labeled manually using the GToBI annotation system. Ten different contour types were identified.The fundamental frequency (F0) of these contours was modeled using third-order orthogonal polynomials, following an approach similar to the one Grabe, Kochanski, and Coleman (2007) used for English. Statistical analyses showed that all but one contour pair differed significantly from each other in at least one of the four coefficients. This demonstrates that polynomial modeling can provide quantitative empirical support for phonological labels in unscripted speech, and for languages other than English. Furthermore, polynomial expressions can be used to derive the alignment of tonal targets relative to the syllable structure, making polynomial modeling more accessible to the phonological research community. Finally, within-contour comparisons of the three age groups showed that for children, the magnitude of the higher coefficients is lower, suggesting that they are not yet able to modulate their pitch as fast as adults

Vitalism as an Epistemological Obstacle to Biochemical Knowledge

This work resulted from the study of Gaston Bachelard’s epistemology in the Logic and Philosophy of Science discipline, Biochemistry Graduate Program, UFRJ, which lead to discussions of epistemological obstacles on biochemical knowledge construction. The aim was to identify barriers to scientific knowledge development in the praxis of graduate students of biochemistry and correlated areas, emphasizing the vitalist (animist) and teleological (unitary and pragmatic obstacles) conceptions. In order to verify whether students, which never attended classes in epistemology, agree or are able to identify the vitalist conception, a questionnaire containing also selected excerpts of scientific papers in high impact factor journals was delivered to thirty graduating students from different courses at UFRJ and other Brazilian universities. Not only those conceptions were accepted or were not recognized, but it was also possible to observe a vitalist approach in the answers. We could also perceive a pragmatic and teleological vision of the evolution process, expressed in apologies of immanent purposes in organisms adaptations. Considering these facts, it is clear the necessity to emphasize the material, non-teleological character of biochemistry/biology, especially in disciplines offered in under-graduate courses