Interactive Visualization and Navigation of Web Search Results Revealing Community Structures and Bridges

International audienceWith the information overload on the Internet, organization and visualization of web search results so as to facilitate faster access to information is a necessity. The classical methods present search results as an ordered list of web pages ranked in terms of relevance to the searched topic. Users thus have to scan text snippets or navigate through various pages before finding the required information. In this paper we present an interactive visualization system for content analysis of web search results. The system combines a number of algorithms to present a novel layout methodology which helps users to analyze and navigate through a collection of web pages. We have tested this system with a number of data sets and have found it very useful for the exploration of data. Different case studies are presented based on searching different topics on Wikipedia through Exalead's search engine

Xenopus laevis and Emerging Amphibian Pathogens in Chile

Amphibians face an extinction crisis with no precedence. Two emerging infectious diseases, ranaviral disease caused by viruses within the genus Ranavirus and chytridiomycosis due to Batrachochytrium dendrobatidis (Bd), have been linked with amphibian mass mortalities and population declines in many regions of the globe. The African clawed frog (Xenopus laevis) has been indicated as a vector for the spread of these pathogens. Since the 1970s, this species has been invasive in central Chile. We collected X. laevis and dead native amphibians in Chile between 2011 and 2013. We conducted post-mortem examinations and molecular tests for Ranavirus and Bd. Eight of 187 individuals (4.3 %) tested positive for Ranavirus: seven X. laevis and a giant Chilean frog (Calyptocephallela gayi). All positive cases were from the original area of X. laevis invasion. Bd was found to be more prevalent (14.4 %) and widespread than Ranavirus, and all X. laevis Bd-positive animals presented low to moderate levels of infection. Sequencing of a partial Ranavirus gene revealed 100 % sequence identity with Frog Virus 3. This is the first report of Ranavirus in Chile, and these preliminary results are consistent with a role for X. laevis as an infection reservoir for both Ranavirus and Bd

Migration Routes of New World Sanderlings (Calidris alba)

We color-marked Sanderlings (Calidris alba Pallas) at 19 locations in 6 countries in the New World and coordinated a network of volunteers to locate banded individuals in migration over a five-year period. The observers reported 252 independent sightings of birds in countries different from the country of banding. Sanderlings that migrate north to the Arctic from Chile and Peru travel principally through the central corridor (Texas and northward) of the United States and Canada; smaller numbers follow the Pacific coast. A few migrate north from the Pacific coast of South America along the Atlantic coast of the United States. Southbound from the Arctic to coastal Chile and Peru, many individuals switch eastward to stopovers on the Atlantic coast, including birds that migrated north along the U.S. Pacific coast. Sanderlings banded in Brazil during the nonbreeding period appear only on the U.S. Atlantic coast in migration. Our results emphasize the individual nature of migration. We found considerable heterogeneity in migratory behavior among individuals that spend the nonbreeding season together on the same beaches. Individuals from widely separated nonbreeding sites often shared similar pathways. In this species and perhaps in others, no simple single migratory route connects breeding with nonbreeding regions

Widespread infection with hemotropic mycoplasmas in free-ranging dogs and wild foxes across six bioclimatic regions of chile

Indexación ScopusBlood samples of 626 rural dogs, 140 Andean foxes (Lycalopex culpaeus), and 83 South American grey foxes (L. griseus) from six bioregions of Chile spanning 3000 km were screened for Mycoplasma DNA by conventional PCR and sequencing. Risk factors of infection were inferred using Generalized Linear Mixed Models and genetic structure by network analyses. Overall, Mycoplasma haemocanis/Mycoplasma haemofelis (Mhc/Mhf) and Candidatus Mycoplasma haematoparvum (CMhp) observed prevalence was 23.8% and 12.8% in dogs, 20.1% and 7.2% in Andean foxes, and 26.5% and 8.4% in grey foxes, respectively. Both hemoplasmas were confirmed in all the bioregions, with higher prevalence in those where ticks from the Rhipicephalus sanguineus species group were absent. Candidatus M. haematominutum and a Mycoplasma sp. previously found in South American carnivores were detected in one fox each. Although the most prevalent Mhc/Mhf and CMhp sequence types were shared between dogs and foxes, network analysis revealed genetic structure of Mhc/Mhf between hosts in some regions. Male sex was associated with a higher risk of Mhc/Mhf and CMhp infection in dogs, and adult age with CMhp infection, suggesting that direct transmission is relevant. No risk factor was identified in foxes. Our study provides novel information about canine hemoplasmas with relevance in distribution, transmission routes, and cross-species transmission. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.https://www.mdpi.com/2076-2607/9/5/91

Genetic Structure and Demographic History Should Inform Conservation: Chinese Cobras Currently Treated as Homogenous Show Population Divergence

An understanding of population structure and genetic diversity is crucial for wildlife conservation and for determining the integrity of wildlife populations. The vulnerable Chinese cobra (Naja atra) has a distribution from the mouth of the Yangtze River down to northern Vietnam and Laos, within which several large mountain ranges and water bodies may influence population structure. We combined 12 microsatellite loci and 1117 bp of the mitochondrial cytochrome b gene to explore genetic structure and demographic history in this species, using 269 individuals from various localities in Mainland China and Vietnam. High levels of genetic variation were identified for both mtDNA and microsatellites. mtDNA data revealed two main (Vietnam + southern China + southwestern China; eastern + southeastern China) and one minor (comprising only two individuals from the westernmost site) clades. Microsatellite data divided the eastern + southeastern China clade further into two genetic clusters, which include individuals from the eastern and southeastern regions, respectively. The Luoxiao and Nanling Mountains may be important barriers affecting the diversification of lineages. In the haplotype network of cytchrome b, many haplotypes were represented within a “star” cluster and this and other tests suggest recent expansion. However, microsatellite analyses did not yield strong evidence for a recent bottleneck for any population or genetic cluster. The three main clusters identified here should be considered as independent management units for conservation purposes. The release of Chinese cobras into the wild should cease unless their origin can be determined, and this will avoid problems arising from unnatural homogenization

Análise do impacto da implantação de sistemas ERP nas características organizacionais das empresas de construção civil

Uma das causas do insucesso do ERP nas empresas de construção civil é o fato da implantação desse sistema ser uma grande mudança organizacional. O objetivo desta pesquisa é identificar como a implementação do sistema ERP impacta na organização e nos processos gerencias das empresas de construção civil. Foi realizada uma survey em uma amostra de empresas construtoras brasileiras. Os dados foram coletados por meio de um questionário encaminhado por email a dois grupos de empresas: com e sem ERP implantado. A partir da análise estatística discriminante foi possível identificar as variáveis relacionadas ao nível de desenvolvimento dos processos de gestão e as características organizacionais que mais distinguem os dois grupos de empresas. Os resultados revelaram que a implantação do ERP impacta nas variáveis da maturidade organizacional nos seguintes aspectos: visão estratégica, relacionamento com cliente, gerenciamento de recursos humanos, gestão financeira e de TI

Uncertainty and Sensitivity Analysis: From Regulatory Requirements to Conceptual Structure and Computational Implementation

Abstract. An approach to the conversion of regulatory requirements into a conceptual and computational structure that permits meaningful uncertainty and sensitivity analyses is descibed. This approach is predicated on the description of the desired analysis in terms of three basic entities: (i) a probability space characterizing aleatory uncertainty, (ii) a probability space characterizing epistemic uncertainty, and (iii) a model that predicts system behavior. The presented approach is illustrated with results from the 2008 performance assessment for the proposed repository for high-level radioactive waste at Yucca Mountain, Nevada. Keywords. Aleatory uncertainty, Epistemic uncertainty, Performance assessment, Regulatory requirements, Sensitivity analysis, Uncertainty analysis Introduction An approach to the conversion of regulatory requirements into a conceptual and computational structure that permits meaningful uncertainty and sensitivity analyses is descibed. This approach is predicated on the description of the desired analysis in terms of three basic entities: (i) a probability space characterizing aleatory uncertainty, (ii) a probability space characterizing epistemic uncertainty, and (iii) a model that predicts system behavior. The presented approach is illustrated with results from the 2008 performance assessment (PA) for the proposed repository for high-level radioactive waste at Yucca Mountain (YM), Nevada, carried out by the U.S. Department of Energy (DOE) to assess compliance with regulations promulgated by the U.S. Nuclear Regulatory Commission (NRC) [1-3]. Example: DOE's Licensing Requirements for YM Repository The NRC's licensing requirements for the YM repository provide a good example of the challenges that are present in the conversion of regulatory requirements into the conceptual structure and associated computational implementation of an analysis that establishes compliance (or noncompliance) with those requirements [4; 5]