Linear Triangle Dynamics: The Pedal Map and Beyond

We present a moduli space for similar triangles, then classify triangle maps $f$ that arise from linear maps on this space, with the well-studied pedal map as a special case. Each linear triangle map admits a Markov partition, showing that $f$ is mixing, hence ergodic.Comment: 11 pages, 4 figure

O Sorriso da Avó em ‘Guarde Segredo’ de Esmeralda Ribeiro

No conto “Guarde Segredo” (1991), Esmeralda Ribeiro (1958-) substitui os pais “verdadeiros” ou biológicos de uma jovem afrodescendente por dois pais “falsos” (vovó Olívia e Lima Barreto). Por qual razão Ribeiro nos apresenta esta família alternativa? Neste artigo, defendo que a imaginação de uma nova família permite a Ribeiro combinar uma abordagem da invisibilidade literária, histórica e política das mulheres afrodescendentes com uma visão crítica e ambivalente da maternidade, quando esta se torna excessivamente visível na esfera privada. Apropriando-se dos princípios utilizados por sociedades disciplinares para regular relações raciais e sexuais, “Guarde Segredo” introduz estruturas panópticas de disciplina (Foucault, 1977) no cotidiano familiar dos inquilinos da casa situada à rua Major Mascarenhas, de modo a inverter o processo de invisibilidade crescente da jovem narradora, enquanto mãe afrodescendente em potência. A solução panóptica encontrada por Ribeiro cria uma plataforma privilegiada de acesso aos seus pais enquanto observadores/educadores, um dos quais é, como veremos, mais invisível do que o outro. A imaginação de uma nova família em “Guarde Segredo” permite a Ribeiro oferecer pistas teóricas necessárias para uma discussão sustentável e não essencialista da maternidade no contexto do projeto político-literário da escritura afro-brasileira

Authentic Recipes from Around the World

This is the author accepted manuscript.This book reflects about the term "authenticity" in the context of foods and drinks. It asks how history, time and temporality can be used to make particular cultural products seem "authentic" or the "real" thing. We explore authenticity in relation to foods and drinks from different parts of the world: pulque (alcoholic drink from central Mexico), flaounes (celebration Easter pies from Cyprus), Welsh craft cider, and acarajé (street snack from Brazil). Temporal categories like "origins," "traditions" and "timelessness" and the emotional connections they can evoke, like feelings of nostalgia and belonging, are at the heart of our approach. The book is part of a larger research project, Consuming Authenticities: Time, Place and the Past in the Construction of Authentic Foods and Drinks, funded by the Arts and Humanities Research Council in relation to their major research theme, Care for the Future: Thinking Forward Through the Past.Arts & Humanities Research Counci

Interactions of inert confiners with explosives

The deformation of an inert confiner by a steady detonation wave in an adjacent explosive is investigated for cases where the confiner is suciently strong (or the explosive suciently weak) such that the overall change in the sound speed of the inert is small. A coupling condition which relates the pressure to the deflection angle along the explosive-inert interface is determined. This includes its dependence on the thickness of the inert, for cases where the initial sound speed of the inert is less than or greater than the detonation speed in the explosive (supersonic and subsonic inert ows, respectively). The deformation of the inert is then solved by prescribing the pressure along the interface. In the supersonic case, the detonation drives a shock into the inert, subsequent to which the ow in the inert consists of alternating regions of compression and tension. In this case reverberations or `ringing' occurs along both the deflected interface and outer edge of the inert. For the subsonic case, the flow in the interior of the inert is smooth and shockless. The detonation in the explosive initially defl ects the smooth interface towards the explosive. For sufficiently thick inerts in such cases, it appears that the deflection of the confiner would either drive the detonation speed in the explosive up to the sound speed of the inert or drive a precursor wave ahead of the detonation in the explosive. Transonic cases, where the inert sound speed is close to the detonation speed, are also considered. It is shown that the confinement affect of the inert on the detonation is enhanced as sonic conditions are approached from either side

Complement C3 variant and the risk of age-related macular degeneration

Background: Age-related macular degeneration is the most common cause of blindness in Western populations. Susceptibility is influenced by age and by genetic and environmental factors. Complement activation is implicated in the pathogenesis.Methods: We tested for an association between age-related macular degeneration and 13 single-nucleotide polymorphisms (SNPs) spanning the complement genes C3 and C5 in case subjects and control subjects from the southeastern region of England. All subjects were examined by an ophthalmologist and had independent grading of fundus photographs to confirm their disease status. To test for replication of the most significant findings, we genotyped a set of Scottish cases and controls.Results: The common functional polymorphism rs2230199 (Arg80Gly) in the C3 gene, corresponding to the electrophoretic variants C3S (slow) and C3F (fast), was strongly associated with age-related macular degeneration in both the English group (603 cases and 350 controls, P=5.9 x 10(sup -5)) and the Scottish group (244 cases and 351 controls, P=5.0 x 10(sup -5)). The odds ratio for age-related macular degeneration in C3 S/F heterozygotes as compared with S/S homozygotes was 1.7 (95% confidence interval [CI], 1.3 to 2.1); for F/F homozygotes, the odds ratio was 2.6 (95% CI, 1.6 to 4.1). The estimated population attributable risk for C3F was 22%.Conclusions: Complement C3 is important in the pathogenesis of age-related macular degeneration. This finding further underscores the influence of the complement pathway in the pathogenesis of this disease