Special Lagrangians, stable bundles and mean curvature flow

We make a conjecture about mean curvature flow of Lagrangian submanifolds of Calabi-Yau manifolds, expanding on \cite{Th}. We give new results about the stability condition, and propose a Jordan-H\"older-type decomposition of (special) Lagrangians. The main results are the uniqueness of special Lagrangians in hamiltonian deformation classes of Lagrangians, under mild conditions, and a proof of the conjecture in some cases with symmetry: mean curvature flow converging to Shapere-Vafa's examples of SLags.Comment: 36 pages, 4 figures. Minor referee's correction

Cross-sensitization between poppy seed and buckwheat in a food-allergic patient with poppy seed anaphylaxis

The opium poppy, Papaver somniferum L., is the source of both poppy seeds and opium. The commercially available seeds are widely used as ingredients for various kinds of food. IgE-mediated sensitization to poppy seeds is rare, but, if present, clinical symptoms are usually severe. Cross-sensitizations between poppy seeds and other food allergens have been described with sesame, hazelnut, rye grain and kiwi fruit. We report the case of a 17-year-old female with an apparently food-allergic reaction after ingestion of a poppy seed cake. Allergological workup revealed a poppy seed anaphylaxis and led to the identification of a novel cross-sensitization with buckwheat. Copyright (c) 2006 S. Karger AG, Basel

Explicit Global Coordinates for Schwarzschild and Reissner-Nordstroem

We construct coordinate systems that cover all of the Reissner-Nordstroem solution with m>|q| and m=|q|, respectively. This is possible by means of elementary analytical functions. The limit of vanishing charge q provides an alternative to Kruskal which, to our mind, is more explicit and simpler. The main tool for finding these global charts is the description of highly symmetrical metrics by two-dimensional actions. Careful gauge fixing yields global representatives of the two-dimensional theory that can be rewritten easily as the corresponding four-dimensional line elements.Comment: 12 pages, 3 Postscript figures, sign error in Eq. (37) and below corrected, references and Note added; to appear in Class. Quantum Gra

Partial dynamical symmetry in Bose-Fermi systems

We generalize the notion of partial dynamical symmetry (PDS) to a system of interacting bosons and fermions. In a PDS, selected states of the Hamiltonian are solvable and preserve the symmetry exactly, while other states are mixed. As a first example of such novel symmetry construction, spectral features of the odd-mass nucleus $^{195}$Pt are analyzed.Comment: 5 pages, 1 figure, 2 tables, accepted for publication in Physical Review C (Rapid Communications

The origin of the grooves on Phobos

Various theories for the long, linear depressions on the surface of Phobos are reviewed. Imagery from Viking Orbiters is used to map the surface distribution of the grooves, study their morphology, and date them by means of the density of superimposed impact craters. Data is presented which tends to support the hypothesis that the deep-seated fracturing was caused by a large, nearly catastrophic cratering event. It is suggested that the grooves were produced during the creation of the Stickney crater, rather than as the result of tidal stresses induced by Mars or by drag forces during the hypothetical capture of the satellite by Mars

'Looking away': private writing techniques as a form of transformational text shaping in art & design and the natural sciences

Despite their long history and wide-spread use, the private writing techniques of journaling and freewriting remain largely underexploited in the field of academic writing instruction. They are seen only as forms of pre-writing, and are criticised by some for being under-theorised, vague and asocial. Contextualizing them within a writing-as-social-practice approach, and drawing on a conceptual framework including a notion of looking-away developed by Derrida, Vygotsky’s conception of learning development, and Ivanic’s notion of writer identity, this paper aims to throw new light on these private writing techniques and argues they can be transformational in developing students’ learning and identity, as well as written and non-written outputs. In this paper we theorise these practices through reflection on two instances of teaching in which they played an important part. The teaching interventions were in different disciplinary contexts (architectural design and Natural Sciences), with writers of different levels of expertise/competence (undergraduate and PhD), in both L1 and multilingual settings. In both interventions, we found that these private writing techniques were transformational due to the space they allowed writers to self-reflect, and to look away from their public-facing outputs. The techniques provided significant developmental benefits and moved the students along a continuum towards a more expert-like identity