Repetition-free longest common subsequence of random sequences

A repetition free Longest Common Subsequence (LCS) of two sequences x and y is an LCS of x and y where each symbol may appear at most once. Let R denote the length of a repetition free LCS of two sequences of n symbols each one chosen randomly, uniformly, and independently over a k-ary alphabet. We study the asymptotic, in n and k, behavior of R and establish that there are three distinct regimes, depending on the relative speed of growth of n and k. For each regime we establish the limiting behavior of R. In fact, we do more, since we actually establish tail bounds for large deviations of R from its limiting behavior. Our study is motivated by the so called exemplar model proposed by Sankoff (1999) and the related similarity measure introduced by Adi et al. (2007). A natural question that arises in this context, which as we show is related to long standing open problems in the area of probabilistic combinatorics, is to understand the asymptotic, in n and k, behavior of parameter R.Comment: 15 pages, 1 figur

Tropical Dry Forest Succession and the Contribution of Lianas to Wood Area Index (WAI)

The transmission and interception of light through the canopy is an important indicator of forest productivity in tropical forest ecosystems, and the amount of light that eventually reaches the forest floor is influenced by its interactions with leaves, branches, fruits, and flowers among many different canopy elements. While most studies of forest canopy light interception focus on leaf area index (LAI), very few studies have examined wood area index (WAI), which may account for a substantial component of light interception in tropical forests. The influence of lianas on the interception of light and their overall contribution to WAI is a potentially important factor, but it is generally overlooked because of its difficulty to assess. In this paper we evaluate the relative contribution that lianas have to the overall WAI and canopy openness as function of successional stage via a latitudinal comparison of sites across the Americas (Mexico, Costa Rica and Brazil). Our results suggest that lianas significantly increase WAI and decreases canopy openness. However, lianas were absent at all of our study sites where canopy openness exceeded 60%. Our data are the first to explicitly document the role of lianas in the estimation of WAI and, overall, they will contribute to better estimations of ecosystem level LAI in tropical environments, where there is a lack of data on WAI

A simple technique can reduce cardiopulmonary bypass use during lung transplantation

Cardiopulmonary bypass causes an inflammatory response and consumption of coagulation factors, increasing the risk of bleeding and neurological and renal complications. Its use during lung transplantation may be due to pulmonary hypertension or associated cardiac defects or just for better exposure of the pulmonary hilum. We describe a simple technique, or open pericardium retraction, to improve hilar exposure by lifting the heart by upward retraction of the pericardial sac. This technique permits lung transplantation without cardiopulmonary bypass when bypass use is recommended only for better exposure

Reversed rainbow with a nonlocal metamaterial

WOS:000347171300050 (Nº de Acesso Web of Science)One of the intriguing potentials of metamaterials is the possibility to realize a nonlocal electromagnetic reaction, such that the effective medium response at a given point is fundamentally entangled with the macroscopic field distribution at long distances. Here, it is experimentally and numerically verified that a microwave nonlocal metamaterial formed by crossed metallic wires enables a low-loss broadband anomalous material response such that the refractive index decreases with frequency. Notably, it is shown that an electromagnetic beam refracted by our metamaterial prism creates a reversed microwave rainbow

Laparoendoscopic single-site (LESS) sacrocolpopexy: feasibility and efficacy of knotless procedure performed with conventional instruments

The aim of this paper was to report a case of a patient with stage IV vaginal vault prolapse treated by laparoendoscopic single-site (LESS) sacrocolpopexy using an Alexis retractor and a surgical glove attached to three trocars through a 3.5-cm umbilical incision. Only conventional laparoscopic instruments were used for intrabdominal dissection of vagina and peritoneum. The mesh was fixed to the vaginal fornix and to the sacral periosteum from the promontory using running sutures hold in the extremities by polymer clips. The posterior peritoneum was closed over the mesh. LESS sacrocolpopexy performed with conventional instruments is a difficult but feasible and efficient technique to treat vaginal vault prolapse that respects the principles of conventional laparoscopic or open repairs. Alexis retractor associated with knotless sutures are technical options that simplify LESS reconstructive surgical maneuvers

Brane-world Quantum Gravity

The Arnowitt-Deser-Misner canonical formulation of general relativity is extended to the covariant brane-world theory in arbitrary dimensions. The exclusive probing of the extra dimensions makes a substantial difference, allowing for the construction of a non-constrained canonical theory. The quantum states of the brane-world geometry are defined by the Tomonaga-Schwinger equation, whose integrability conditions are determined by the classical perturbations of submanifolds contained in the Nash's differentiable embedding theorem. In principle, quantum brane-world theory can be tested by current experiments in astrophysics and by near future laboratory experiments at Tev energy. The implications to the black-hole information loss problem, to the accelerating cosmology, and to a quantum mathematical theory of four-sub manifolds are briefly commented.Comment: 14 pages, no figures, JHEP format, to appear in JHEP April 200

Early social interactions: an analysis of changes in the parental role

As interações físicas e afetivas estabelecidas entre progenitores e seus descendentes vêm sendo rediscutidas na ciência psicológica, em virtude de contribuições recentes oferecidas pela Psicologia do Desenvolvimento Evolucionista (PDE). Pretende-se, no presente artigo, fazer uma revisão das teorias clássicas e contemporâneas que trataram de explicar os fatores implicados na gênese, no desenvolvimento e na função das interações precoces entre filhos e mães e pais. Buscar-se-á estabelecer as modalidades de vinculação em diferentes espécies, a partir de uma abordagem evolucionista, até se chegar à conduta de apego e à sua contraparte, o comportamento parental, em sua dinâmica normal e patogênica, na espécie homo. A psicopatologia do vínculo mãe-bebê, em especial a depressão puerperal, será analisada tendo como pano de fundo a contradição entre as características biológicas da espécie e as exigências culturais que as sociedades industrializadas impõe à mãe e ao pai, destacando papel que o investimento paterno e aloparental assumem no desenvolvimento favorável do bebê e, conseqüentemente, no re-estabelecimento da puérpera.The physical and emotional interactions established between ancestors and descendants have been reexamined in psychological science due to recent contributions offered by Evolutionary Psychology. This article reviews classic and contemporary theories of distinct philosophical backgrounds, which have tried to explain the factors implied in the genesis, development and function of the early interactions between children and their parents. A review of papers from distinct areas regarding attachment behavior and parental behavior, in its normal and pathogenic dynamics in the species homo, is presented. The psychopathology of the child's tie to the mother and its disruption through separation, deprivation and bereavement, especially puerperal depression, are analyzed, as well as the role that the paternal care assumes in this context, in order to provide the human infant with an ideal environment for optimal growth both psychologically and physiologically

Spatially confined UHF RFID detection with a metamaterial grid

WOS: 000329516700044 (Nº de Acesso Web of Science)The confinement of the detection region is one of the most challenging issues in Ultra-High Frequency (UHF) Radio Frequency Identification (RFID) systems. Here, we propose a new paradigm to confine the interrogation zone of standard UHF RFID systems. Our approach relies on the use of an all-planar metamaterial wire grid to block the radiation field (i.e., the far-field) of the reader antenna, and thereby obtain a spatially well-confined detection region in the near-field. This solution is analytically and numerically investigated, and then experimentally verified through near-field and tag-reading measurements, demonstrating its effectiveness and robustness under external perturbations

A comparison between overweight cutoff points for detection of high blood pressure in adolescents

OBJETIVOS: Avaliar a acurácia de três pontos de corte na determinação da pressão arterial elevada em adolescentes, dada a forte relação entre o excesso de peso e valores elevados de pressão arterial. MÉTODOS: Participaram do estudo 1.021 adolescentes de ambos os sexos, selecionados de maneira aleatória nas escolas públicas e particulares de Londrina (PR). O peso corporal foi aferido por meio de balança digital, e a estatura, por um estadiômetro portátil com extensão máxima de 2 metros. A pressão arterial foi avaliada através de um aparelho automático. A capacidade do índice de massa corporal de detectar a pressão arterial elevada foi averiguada por meio da curva ROC e seus parâmetros (sensibilidade, especificidade e área sob a curva). RESULTADOS: Os pontos de corte da proposta nacional apresentaram maior acurácia (masculino: 0,636±0,038; feminino: 0,585±0,043) quando comparados aos pontos de corte das propostas internacional (masculino: 0,594±0,040; feminino: 0,570±0,044) e norte-americana (masculino: 0,612±0,039; feminino: 0,578±0,044). CONCLUSÃO: A proposta nacional foi a que apresentou melhor acurácia na indicação de valores elevados de pressão arterial.OBJECTIVES: To evaluate the accuracy of three different cutoff points for the detection of high blood pressure in adolescents, given the strong relationship between overweight and high blood pressure levels. METHODS: A total of 1,021 adolescents of both sexes were enrolled in the study, selected at random from public and private schools in Londrina, Brazil. Their body weight was measured using a digital balance, and their height with a portable stadiometer with a maximum extension of 2 meters. Arterial blood pressure was measured using an automatic apparatus. The capacity of body mass index to detect high blood pressure was gauged using ROC curves and their parameters (sensitivity, specificity, and area under the curve). RESULTS: The cutoff points proposed in a Brazilian standard exhibited greater accuracy (males: 0.636±0.038; females: 0.585±0.043) than the cutoff points proposed in an international (males: 0.594±0.040; females: 0.570±0.044) and a North-American standard (males: 0.612±0.039; females: 0.578±0.044). CONCLUSIONS: The Brazilian proposal offered greatest accuracy for indicating high blood pressure levels