1,107 research outputs found

    Lyndon Array Construction during Burrows-Wheeler Inversion

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    In this paper we present an algorithm to compute the Lyndon array of a string TT of length nn as a byproduct of the inversion of the Burrows-Wheeler transform of TT. Our algorithm runs in linear time using only a stack in addition to the data structures used for Burrows-Wheeler inversion. We compare our algorithm with two other linear-time algorithms for Lyndon array construction and show that computing the Burrows-Wheeler transform and then constructing the Lyndon array is competitive compared to the known approaches. We also propose a new balanced parenthesis representation for the Lyndon array that uses 2n+o(n)2n+o(n) bits of space and supports constant time access. This representation can be built in linear time using O(n)O(n) words of space, or in O(nlogn/loglogn)O(n\log n/\log\log n) time using asymptotically the same space as TT

    Out-of-phase oscillation between superfluid and thermal components for a trapped Bose condensate under oscillatory excitation

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    The vortex nucleation and the emergence of quantum turbulence induced by oscillating magnetic fields, introduced by Henn E A L, et al. 2009 (Phys. Rev. A 79, 043619) and Henn E A L, et al. 2009 (Phys. Rev. Lett. 103, 045301), left a few open questions concerning the basic mechanisms causing those interesting phenomena. Here, we report the experimental observation of the slosh dynamics of a magnetically trapped 87^{87}Rb Bose-Einstein condensate (BEC) under the influence of a time-varying magnetic field. We observed a clear relative displacement in between the condensed and the thermal fraction center-of-mass. We have identified this relative counter move as an out-of-phase oscillation mode, which is able to produce ripples on the condensed/thermal fractions interface. The out-of-phase mode can be included as a possible mechanism involved in the vortex nucleation and further evolution when excited by time dependent magnetic fields.Comment: 5 pages, 5 figures, 25 reference

    Deep multiband surface photometry on star forming galaxies: II. A volume limited sample of 21 emission lines galaxies

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    We present deep surface photometry of a volume--limited sample of 21 UM emission line galaxies in broadband optical UBVRI and near infra-red (NIR) HKs filters. The sample comprises 19 blue compact galaxies (BCGs) and two spirals. For some targets the exposure times are the deepest to date. For the BCG UM462 we observe a previously undetected second disk component beyond a surface brightness level of mu_B=26 mag arcsec^{-2}. This is a true low surface brightness component with central surface brightness mu_0=24.1 mag arcsec^{-2} and scale length h_r=1.5 kpc. All BCGs are dwarfs, with M_B>=-18, and very compact, with an average scale length of h_r~1 kpc. We separate the burst and host populations for each galaxy and compare them to stellar evolutionary models with and without nebular emission contribution. We also measure the A_{180} asymmetry in all filters and detect a shift from optical to NIR in the average asymmetry of the sample. This shift seems to be correlated with the morphological class of the BCGs. Using the color-asymmetry relation, we identify five BCGs in the sample as mergers, which is confirmed by their morphological class. Though clearly separated from normal galaxies in the concentration-asymmetry parameter space, we find that it is not possible to distinguish luminous starbursting BCGs from the merely star forming low luminosity BCGs.Comment: 48 pages, 39 figures, submitte

    Congenital adrenal hyperplasia: a qualitative study on disease and treatment, doubts, anguishes and relationships (part I)

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    OBJECTIVE: To understand the meanings/thoughts of a group of parents, patients and physicians regarding congenital adrenal hyperplasia (CAH), and to evaluate their anguishes, doubts and anxieties. METHODS: We selected 21 subjects: 7 pediatric endocrinologists from five Brazilian Public Health System institutions, 9 parents and 6 patients with CAH, according to the qualitative research model. Three of the studied categories are presented: disease and treatment, doubts and anguishes and relationships. RESULTS: Parents' main anguishes relate to the situation of an unnamed sex at birth. A sense of loneliness when dealing with the disease is the major anguish among patients, whereas physicians show hopelessness with the passivity parents and patients. CONCLUSIONS: The apparent submissiveness of patients/parents during consultations must be evaluated cautiously. University Hospitals outpatient clinic dynamics have a direct effect on this behavior: physicians do not talk openly with parents who in turn do not talk with their children, whereas patients chose to protect their parents from additional suffering. Thus, some miscommunication is noticeable among these subjects. These observations suggest that a special mindful measure should be built for these patients.OBJETIVO: Compreender significados e pensamentos de um grupo de pais, pacientes e médicos sobre a hiperplasia adrenal congênita (HAC) e analisar angústias, dúvidas e ansiedades. MÉTODOS: Foram selecionados 21 sujeitos: 7 especialistas de cinco instituições do Sistema Único de Saúde (SUS), 9 familiares e 6 pacientes com HAC, seguindo padrões da pesquisa qualitativa. Neste artigo, apresentaram-se três categorias: doença e tratamento, dúvidas e angústias e relacionamentos. RESULTADOS: As principais angústias dos pais relacionam-se à indefinição sexual ao nascimento. Para pacientes, a angústia maior relaciona-se ao sentimento de solidão ao lidar com a doença e seu tratamento, enquanto médicos mostram-se inconformados com a passividade dos pais/pacientes. CONCLUSÕES: A passividade de pacientes/familiares nas consultas deve ser avaliada com cautela, pois a dinâmica do ambulatório dos hospitais-escola tem efeito neste comportamento: os médicos não conversam abertamente com os pais, enquanto estes não conversam com seus filhos, que, por sua vez, poupam os pais de mais sofrimento. Constatou-se dificuldade de comunicação entre esses vários sujeitos. Essas observações permitem sugerir que uma medida especial de atenção a esses pacientes deva ser construída.Universidade Federal de São Paulo (UNIFESP) Departamento de MedicinaHospital Infantil Darcy VargasUNIFESP Departamento de PediatriaHospital e Maternidade São LuizUNIFESP, Depto. de MedicinaUNIFESP, Depto. de PediatriaSciEL
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