Erratum: Small-world networks: Evidence for a crossover picture

We correct the value of the exponent \tau.Comment: 2 pages, 1 figur

Similar impact of topological and dynamic noise on complex patterns

Shortcuts in a regular architecture affect the information transport through the system due to the severe decrease in average path length. A fundamental new perspective in terms of pattern formation is the destabilizing effect of topological perturbations by processing distant uncorrelated information, similarly to stochastic noise. We study the functional coincidence of rewiring and noisy communication on patterns of binary cellular automata.Comment: 8 pages, 7 figures. To be published in Physics Letters

An Additional Pulsating Mode (7.35 mHz) and Pulsations Timing Variations of PG 1613+426

We present the detection of an additional pulsation mode (7.35 mHz) of a subdwarf B star, PG 1613+426, and periodic Observed minus Calculated (O-C) variations for two existing pulsations. PG 1613+426 is near the hot end of the sdB instability strip. One pulsation mode (6.94 mHz) was detected so far by Bonanno et al. (2002) and another pulsation mode candidate (7.05 mHz) was proposed with a confidence level above 90% by Kuassivi and Ferlet (2005). To constrain sdB star evolutional scenarios, this star was monitored in 2010, 2011, 2015, and 2017 as a part of a project for finding companions to sdB stars using the pulsation timing method. The photometric analysis of those data shows an additional 7.35 mHz pulsation mode as well as the previously detected 6.93 mHz mode. However the 7.05 mHz mode was not detected. Nightly amplitude changes of 7.35 mHz mode were observed in the 2011 data, however the 2017 data did not show nightly amplitude shifts. O-C variations were detected in both 6.93 mHz and 7.35 mHz pulsations, indicating that PG 1613+426 may have a low mass companion star. However, more observations are needed to confirm it

Characterization and Modeling of weighted networks

We review the main tools which allow for the statistical characterization of weighted networks. We then present two case studies, the airline connection network and the scientific collaboration network, which are representative of critical infrastructures and social systems, respectively. The main empirical results are (i) the broad distributions of various quantities and (ii) the existence of weight-topology correlations. These measurements show that weights are relevant and that in general the modeling of complex networks must go beyond topology. We review a model which provides an explanation for the features observed in several real-world networks. This model of weighted network formation relies on the dynamical coupling between topology and weights, considering the rearrangement of weights when new links are introduced in the system.Comment: Proceedings of the conference "Complex networks: structure, function and processes", Kolkata (Satellite Meeting of STATPHYS 22), to be published in Physica

Estado, políticas sociais brasileiras e migração haitiana

In order to contribute to the debate on the permanence of Haitian immigrants in Brazil, this paper aims to identify and analyze Haitian immigrants' understandings about Brazilian social policies limited set out to attend to their demands. This is qualitative research, carried out with six Haitian immigrants residing in the municipality of Cambé (PR) between 2016 and 2018. The methodological procedures were organized in three stages: literature review, documental survey, and field research. Data collected through semi-structured interviews show the rediscovery of another model of interventional State by Haitian immigrants in Brazil when compared to the Haitian State, showing limitations in care. Those limitations are six-fold in the following: conditional employment availability; greater availability in the education of immigrant children, and reduced access by adults; free public health services and situations of racism and prejudice in care; difficulties in recognizing professional training diplomas from Haiti.Buscando contribuir al debate sobre la presencia de inmigrantes haitianos en Brasil, este trabajo tiene como objetivo identificar y analizar la comprensión de los inmigrantes haitianos sobre las políticas sociales brasileñas delimitadas para atender sus demandas. Se trata de una investigación cualitativa, realizada con seis inmigrantes haitianos residentes en el municipio de Cambé (Paraná) entre 2016 y 2018. Los procedimientos metodológicos se organizaron en tres partes: revisión bibliográfica, levantamiento documental e investigación de campo. Los datos recolectados a través de entrevistas semiestructuradas muestran el redescubrimiento de otro modelo de Estado intervencionista por parte de los inmigrantes haitianos en Brasil en comparación con el Estado haitiano. Este trabajo evidenció limitaciones en la atención, tales como: disponibilidad de empleo condicional; mayor disponibilidad en la educación de los niños inmigrantes y menor acceso a los adultos; los servicios de salud pública gratuitos y situaciones de racismo y prejuicio en la atención; dificultades para reconocer los títulos de formación profesional de Haití.  Buscando contribuir para o debate sobre a presença dos imigrantes haitianos no Brasil, este trabalho tem como objetivo identificar e analisar as compreensões deles acerca das políticas sociais brasileiras delimitadas ao atendimento de suas demandas. Trata-se de uma pesquisa de natureza qualitativa, realizada com seis imigrantes haitianos residentes no município de Cambé (PR) entre 2016 e 2018. Os procedimentos metodológicos foram organizados em três momentos: revisão bibliográfica, levantamento documental e pesquisa de campo. Dados captados por meio de entrevistas semiestruturadas evidenciam a redescoberta de outro modelo de Estado interventivo pelos imigrantes haitianos no Brasil ao compararem ao Estado haitiano, evidenciando limitações nos atendimentos, tais como: disponibilidade de emprego condicionada; maior disponibilidade na educação das crianças imigrantes e acesso reduzido pelos adultos; a gratuidade dos serviços de saúde pública e situações de racismo e preconceito nos atendimentos; dificuldades para reconhecimento dos diplomas da formação profissional no Haiti

Truncation of power law behavior in "scale-free" network models due to information filtering

We formulate a general model for the growth of scale-free networks under filtering information conditions--that is, when the nodes can process information about only a subset of the existing nodes in the network. We find that the distribution of the number of incoming links to a node follows a universal scaling form, i.e., that it decays as a power law with an exponential truncation controlled not only by the system size but also by a feature not previously considered, the subset of the network ``accessible'' to the node. We test our model with empirical data for the World Wide Web and find agreement.Comment: LaTeX2e and RevTeX4, 4 pages, 4 figures. Accepted for publication in Physical Review Letter

Mitochondrial DNA Variation Reveals a Sharp Genetic Break within the Distribution of the Blue Land Crab Cardisoma guanhumi in the Western Central Atlantic

The blue land crab Cardisoma guanhumi is widely distributed throughout tropical and subtropical estuarine regions in the Western Central Atlantic (WCA). Patterns of population genetic structure and historical demographics of the species were assessed by mtDNA control region sequence analysis to examine the connectivity among five populations (n = 97) within the region for future conservation strategies and decision-making of fishery management. A total of 234 polymorphic nucleotides were revealed within the sequence region, which have defined 93 distinct haplotypes. No dominant mtDNA haplotypes were found but instead a distribution of a few low-frequency recurrent haplotypes with a large number of singletons. A NJ-tree and a median-joining haplotype network revealed two distinct clusters, corresponding to individuals from estuaries located along the Caribbean Sea and Brazilian waters, respectively. AMOVA and FST statistics supported the hypothesis that two main geographic regions exists. Phylogeographical discontinuity was further demonstrated by the Bayesian assignment analysis and a significant pattern of isolation-by-distance. Additionally, tests of neutral evolution and analysis of mismatch distribution indicate a complex demographic history in the WCA, which corresponds to bottleneck and subsequent population growth. Overall, a sharp genetic break between Caribbean and Brazilian populations raised concerns over the conservation status of the blue land crab

Small-world networks: Evidence for a crossover picture

Watts and Strogatz [Nature 393, 440 (1998)] have recently introduced a model for disordered networks and reported that, even for very small values of the disorder $p$ in the links, the network behaves as a small-world. Here, we test the hypothesis that the appearance of small-world behavior is not a phase-transition but a crossover phenomenon which depends both on the network size $n$ and on the degree of disorder $p$. We propose that the average distance $\ell$ between any two vertices of the network is a scaling function of $n / n^*$. The crossover size $n^*$ above which the network behaves as a small-world is shown to scale as $n^*(p \ll 1) \sim p^{-\tau}$ with $\tau \approx 2/3$.Comment: 5 pages, 5 postscript figures (1 in color), Latex/Revtex/multicols/epsf. Accepted for publication in Physical Review Letter

The effects of spatial constraints on the evolution of weighted complex networks

Motivated by the empirical analysis of the air transportation system, we define a network model that includes geographical attributes along with topological and weight (traffic) properties. The introduction of geographical attributes is made by constraining the network in real space. Interestingly, the inclusion of geometrical features induces non-trivial correlations between the weights, the connectivity pattern and the actual spatial distances of vertices. The model also recovers the emergence of anomalous fluctuations in the betweenness-degree correlation function as first observed by Guimer\`a and Amaral [Eur. Phys. J. B {\bf 38}, 381 (2004)]. The presented results suggest that the interplay between weight dynamics and spatial constraints is a key ingredient in order to understand the formation of real-world weighted networks