On Quasiperiodic Morphisms

Weakly and strongly quasiperiodic morphisms are tools introduced to study quasiperiodic words. Formally they map respectively at least one or any non-quasiperiodic word to a quasiperiodic word. Considering them both on finite and infinite words, we get four families of morphisms between which we study relations. We provide algorithms to decide whether a morphism is strongly quasiperiodic on finite words or on infinite words.Comment: 12 page

Comparison of the Oxidation State of Fe in Comet 81P/Wild 2 and Chondritic-Porous Interplanetary Dust Particles

The fragile structure of chondritic-porous interplanetary dust particles (CP- IDPs) and their minimal parent-body alteration have led researchers to believe these particles originate in comets rather than asteroids where aqueous and thermal alteration have occurred. The solar elemental abundances and atmospheric entry speed of CP-IDPs also suggest a cometary origin. With the return of the Stardust samples from Jupiter-family comet 81P/Wild 2, this hypothesis can be tested. We have measured the Fe oxidation state of 15 CP-IDPs and 194 Stardust fragments using a synchrotron-based x-ray microprobe. We analyzed ~300 nanograms of Wild 2 material - three orders of magnitude more material than other analyses comparing Wild 2 and CP-IDPs. The Fe oxidation state of these two samples of material are >2{\sigma} different: the CP-IDPs are more oxidized than the Wild 2 grains. We conclude that comet Wild 2 contains material that formed at a lower oxygen fugacity than the parent body, or parent bodies, of CP-IDPs. If all Jupiter-family comets are similar, they do not appear to be consistent with the origin of CP-IDPs. However, comets that formed from a different mix of nebular material and are more oxidized than Wild 2 could be the source of CP-IDPs.Comment: Earth and Planetary Science Letters, in pres

Analysis of Performance of Management Processes in Urban Sand Beaches: Montevideo (De los Pocitos Beach)

As condições em que serviços e atividades direcionadas ao lazer são oferecidas em praias turísticas afeta diretamente o seu desempenho como destino. O gerenciamento nesses ambientes pode ter uma administração efetiva por meio da aplicação de normativas, tal como a ISO/TC 228/WG 5. Essa norma busca auxiliar na prestação de serviços, garantindo a satisfação pelo melhor desempenho das atividades de serviço de forma geral. Este trabalho objetiva analisar o desempenho dos serviços e atividades oferecidos na Playa de los Pocitos (Montevideo, Uruguai), a fim de verificar o desempenho da gestão turística local. Na metodologia aplicouse um formulário para avaliação de desempenho, adaptado aos critérios da ISO/TC 228/WG 5, em que se avaliaram condicionantes por meio da descrição de quatro diferentes cenários, variando de ruim a muito bom. Os avaliadores selecionaram o cenário que condizia à realidade local no momento da pesquisa. Com intuito de servir de base para um processo de diagnóstico da gestão turística vigente, foi observado que ambientes turísticos costeiros ainda não são geridos de forma efetiva e otimizada, e necessitam da aplicação de ferramentas de análise para localizar os quesitos que merecem atenção para, assim, alcançar a melhoria da gestão. Foram constatadas algumas debilidades na gestão turística da Playa de los Pocitos, principalmente em categorias essenciais como Serviços Sanitários, Limpeza e InformaçãoThe quality of leisure services and activities provided on tourist beaches are directly affected by its performance as a destination. Coastal Management can be efficiently conducted through the application of standards in these envi-ronments, such as ISO / TC 228 / WG 5. These standards aim to assist in providing services and ensuring satisfaction for better performance. This work aims to analyze the performance of the services and activities offered in the De los Pocitos beach (Montevideo, Uruguay), in order to verify the performance of the local tourist management. A performance evaluation form was applied, adapted to the criteria of ISO / TC 228 / WG 5, in which the conditions were evaluated through the description of four different scenarios, ranging from bad to very good. The evaluators selected the scenario that corresponded to the local realityat the time of the survey. This proposal found some weaknesses in the tourist management of the beach, mainly in basic categories as Sanitary Services, Cleanliness and Information. To serve as a basis for a process of diagnosis of tourism management, this research observed that coastal tourist environments are not yet managed in an effective and optimized way, and require the application of analysis tools to locate the items that deserve attention improvement of management

Adding a Brane to the Brane-Anti-Brane Action in BSFT

We attempt to generalize the effective action for the D-brane-anti-D-brane system obtained from boundary superstring field theory (BSFT) by adding an extra D-brane to it to obtain a covariantized action for 2 D-branes and 1 anti-D-brane. We discuss the approximations made to obtain the effective action in closed form. Among other properties, this effective action admits solitonic solutions of codimension 2 (vortices) when one of the D-brane is far separated from the brane-anti-brane pair.Comment: 23 pages, 2 figures, minor revision

Quasi Stable Black Holes at the Large Hadron Collider

We adress the production of black holes at LHC and their time evolution in space times with compactified space like extra dimensions. It is shown that black holes with life times of hundred fm/c can be produced at LHC. The possibility of quasi-stable remnants is discussed.Comment: 4 pages, 3 figures, typos removed, omitted factors included, accepted for publicatio

N=1* in 5 dimensions: Dijkgraaf-Vafa meets Polchinski-Strassler

One of the powerful techniques to analyze the 5 dimensional Super Yang Mills theory with a massive hypermultiplet (N=1*) is provided by the AdS/CFT correspondence. It predicts that, for certain special values of the hypermultiplet mass, this theory develops nonperturbative branches of the moduli space as well as new light degrees of freedom. We use the higher dimensional generalization of the matrix model/gauge theory correspondence and recover all the prediction of the supergravity analysis. We construct the map between the four dimensional holomorphic superpotential and the five dimensional action and explicitly show that the superpotential is flat along the nonperturbative branches. This is the first instance in which the Dijkgraaf-Vafa method is used to analyze intrinsically higher dimensional phenomena.Comment: 28 pages, Late

An Improved Brane Anti-Brane Action from Boundary Superstring Field Theory and Multi-Vortex Solutions

We present an improved effective action for the D-brane-anti-D-brane system obtained from boundary superstring field theory. Although the action looks highly non-trivial, it has simple explicit multi-vortex (i.e. codimension-2 multi-BPS D-brane) multi-anti-vortex solutions. The solutions have a curious degeneracy corresponding to different ``magnetic'' fluxes at the core of each vortex. We also generalize the brane anti-brane effective action that is suitable for the study of the inflationary scenario and the production of defects in the early universe. We show that when a brane and anti-brane are distantly separated, although the system is classically stable it can decay via quantum tunneling through the barrier.Comment: 24 pages, 1 figure, JHEP3.cls; v2: references added, tunneling rate discussion expande

Exact Description of D-branes via Tachyon Condensation

We examine the fluctuations around a Dp-brane solution in an unstable D-brane system using boundary states and also boundary string field theory. We show that the fluctuations correctly reproduce the fields on the Dp-brane. Plugging these into the action of the unstable D-brane system, we recover not only the tension and RR charge, but also full effective action of the Dp-brane exactly. Our method works for general unstable D-brane systems and provides a simple proof of D-brane descent/ascent relations under the tachyon condensation. In the lowest dimensional unstable D-brane system, called K-matrix theory, D-branes are described in terms of operator algebra. We show the equivalence of the geometric and algebraic descriptions of a D-brane world-volume manifold using the equivalence between path integral and operator formulation of the boundary quantum mechanics. As a corollary, the Atiyah-Singer index theorem is naturally obtained by looking at the coupling to RR-fields. We also generalize the argument to type I string theory.Comment: 63 pages, LaTeX, no figures, v2: references adde

Use of intrauterine devices and risk of human immunodeficiency virus acquisition among insured women in the United States

Concerns have been raised about progestin-containing contraceptives and the risk of human immunodeficiency virus (HIV) acquisition. Based on health insurance data from women in the United States with intrauterine device (IUD) insertions during 2011-2018, there was no increased risk of incident HIV diagnosis for levonorgestrel-releasing IUDs versus copper IUDs