140 research outputs found

    The power of A/B testing under interference

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    In this paper, we address the fundamental statistical question: how can you assess the power of an A/B test when the units in the study are exposed to interference? This question is germane to many scientific and industrial practitioners that rely on A/B testing in environments where control over interference is limited. We begin by proving that interference has a measurable effect on its sensitivity, or power. We quantify the power of an A/B test of equality of means as a function of the number of exposed individuals under any interference mechanism. We further derive a central limit theorem for the number of exposed individuals under a simple Bernoulli switching interference mechanism. Based on these results, we develop a strategy to estimate the power of an A/B test when actors experience interference according to an observed network model. We demonstrate how to leverage this theory to estimate the power of an A/B test on units sharing any network relationship, and highlight the utility of our method on two applications - a Facebook friendship network as well as a large Twitter follower network. These results yield, for the first time, the capacity to understand how to design an A/B test to detect, with a specified confidence, a fixed measurable treatment effect when the A/B test is conducted under interference driven by networks.Comment: 14 page

    Converting ALC Connection Proofs into ALC Sequents

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    The connection method has earned good reputation in the area of automated theorem proving, due to its simplicity, efficiency and rational use of memory. This method has been applied recently in automatic provers that reason over ontologies written in the description logic ALC. However, proofs generated by connection calculi are difficult to understand. Proof readability is largely lost by the transformations to disjunctive normal form applied over the formulae to be proven. Such a proof model, albeit efficient, prevents inference systems based on it from effectively providing justifications and/or descriptions of the steps used in inferences. To address this problem, in this paper we propose a method for converting matricial proofs generated by the ALC connection method to ALC sequent proofs, which are much easier to understand, and whose translation to natural language is more straightforward. We also describe a calculus that accepts the input formula in a non-clausal ALC format, what simplifies the translation.Comment: In Proceedings PxTP 2019, arXiv:1908.08639. Thanks to CAPES: Coordination for the Improvement of Higher Level Personne

    A connection method for a defeasible extension of ALCH\mathcal{ALCH}

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    This paper proposes a connection method \`a la Bibel for an exception-tolerant family of description logics (DLs). As for the language, we assume the DL ALCH\mathcal{ALCH} extended with two typicality operators: one on (complex) concepts and one on role names. The language is a variant of defeasible DLs, as broadly studied in the literature over the past decade, in which most of these can be embedded. We revisit the definition of the matrix representation of a knowledge base and establish the conditions for a given axiom to be provable. We show that the calculus terminates and is sound and complete w.r.t. a DL version of the preferential semantics widely adopted in non-monotonic reasoning

    MultiFarm: A benchmark for multilingual ontology matching

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    In this paper we present the MultiFarm dataset, which has been designed as a benchmark for multilingual ontology matching. The MultiFarm dataset is composed of a set of ontologies translated in different languages and the corresponding alignments between these ontologies. It is based on the OntoFarm dataset, which has been used successfully for several years in the Ontology Alignment Evaluation Initiative (OAEI). By translating the ontologies of the OntoFarm dataset into eight different languages – Chinese, Czech, Dutch, French, German, Portuguese, Russian, and Spanish – we created a comprehensive set of realistic test cases. Based on these test cases, it is possible to evaluate and compare the performance of matching approaches with a special focus on multilingualism

    Corporate Culture of Contemporary Research University in Search of Complementarity of Humanitarian and Commercial Principles in Education (Russian Context)

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    Background: In the paper the formation of world-class research universities is analysed. The paper studies the history of the research university, prerequisites of its appearance, formation and its development toward modern research university. The modern research university is being cautiously viewed nowadays. The crisis of the university is its reality. The question of the corporate culture formation is now considered to be a topical matter in connection with globalization process, Methods: The authors implemented comparative analysis by comparing Humboldt's model of the research university and the modern one. Results: The comparison is made in regard to the idea of university, its criteria and mission. Special emphasis is laid on the analysis and comparison of corporate culture systems. Conclusions: Corporate culture is a novel criterion of the classical university that has recently arisen in the information society and now characterizes the university in a complementary way: on the one hand, as a competitive market entity, and on the other hand, as a guardian of its traditional, historically formed humanitarian criteria, ideas and mission. The following conclusion has been reached: the updated parameters have the identical form to those found by W. von Humboldt, only essence has changed

    Surto de sarampo na regiao metropolitana de Campinas, SP

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    O Brasil não apresenta circulação endêmica do vírus do sarampo desde o ano 2000. Entre maio e junho de 2011, a Região Metropolitana de Campinas, Estado de São Paulo, registrou três casos de sarampo. Foram descritos casos, as medidas de controle, a busca de possível fonte e de casos secundários. A caracterização genotípica do vírus identificou o genótipo D4, circulante no continente europeu. Não foram encontrados casos índice ou secundários. As medidas de controle efetuadas, aliadas à cobertura vacinal adequada da Região Metropolitana de Campinas contribuíram para que a transmissão da doença fosse interrompida

    Measles outbreak in the metropolitan region of Campinas, Sao Paulo State, Brazil

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    O Brasil não apresenta circulação endêmica do vírus do sarampo desde o ano 2000. Entre maio e junho de 2011, a Região Metropolitana de Campinas, Estado de São Paulo, registrou três casos de sarampo. Foram descritos casos, as medidas de controle, a busca de possível fonte e de casos secundários. A caracterização genotípica do vírus identificou o genótipo D4, circulante no continente europeu. Não foram encontrados casos índice ou secundários. As medidas de controle efetuadas, aliadas à cobertura vacinal adequada da Região Metropolitana de Campinas contribuíram para que a transmissão da doença fosse interrompida.Brasil no presenta circulación endémica del virus sarampión desde el año 2000. Entre mayo y junio de 2011, la Región Metropolitana de Campinas, Estado de Sao Paulo, registró tres casos de sarampión. Se describieron los casos, las medidas de control, la búsqueda de la posible fuente y de casos secundarios. La caracterización genotípica del virus identificó el genotipo D4. No se encontraron casos índices o secundarios. Las medidas de control efectuadas, aliadas a la adecuada cobertura de la vacuna en la Región Metropolitana de Campinas contribuyeron para que la transmisión de la enfermedad fuera interrumpida.Brazil has not had endemic circulation of the measles virus since 2000. Between May and June 2011, the Metropolitan Region of Campinas, State of Sao Paulo, Southeastern Brazil, reported three cases of measles. This report presents a descriptive study of the cases, control measures, and the search for a possible source and secondary cases. The genotypic characterization of the virus identified genotype D4, circulating in Europe. Secondary cases or index case were not found. The control measures and adequate vaccination coverage in Metropolitan Region of Campinas contributed to the interruption of disease transmission

    Comparative yield of different active TB case finding interventions in a large urban TB project in central Uganda: a descriptive study

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    Introduction: Systematic screening for TB among patients presenting to care and among high risk populations is recommended to improve TB case finding. We aimed to describe the comparative yield of three TB screening approaches implemented by a large urban TB project in central Uganda. Methods: We abstracted data on the screening cascade from 65 health facilities and their surrounding communities (numbers screened, with presumptive TB, receiving a diagnostic test and diagnosed with TB) from the different clinic and community TB registers. Results: From January 2018 to December 2019, 93,378 (24%) of all patients screened at health facilities had presumptive TB; 77,381 (82.9%) received a diagnostic test and 14,305 (18.5%) were diagnosed with TB. The screening yield (the number of patients diagnosed with TB out of all patients screened) was 0.3% and was three times higher among men than women (0.6% vs 0.2% p<0.01). During targeted community screening interventions, 9874 (21.1%) of all patients screened had presumptive TB; 7034 (71.2%) of these received a diagnostic test and 1699 (24.2%) were diagnosed with TB. The screening yield was higher among men, (3.7% vs 3.3% p<0.01) and highest among children 0-14 (4.8% vs 3.2% p<0.01). Conclusion: Targeted community TB screening interventions improve access to TB diagnosis for men and children 0-14 years

    The SARS-CoV-2 SSHHPS Recognized by the Papain-like Protease

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    Viral proteases are highly specific and recognize conserved cleavage site sequences of ∼6–8 amino acids. Short stretches of homologous host–pathogen sequences (SSHHPS) can be found spanning the viral protease cleavage sites. We hypothesized that these sequences corresponded to specific host protein targets since >40 host proteins have been shown to be cleaved by Group IV viral proteases and one Group VI viral protease. Using PHI-BLAST and the viral protease cleavage site sequences, we searched the human proteome for host targets and analyzed the hit results. Although the polyprotein and host proteins related to the suppression of the innate immune responses may be the primary targets of these viral proteases, we identified other cleavable host proteins. These proteins appear to be related to the virus-induced phenotype associated with Group IV viruses, suggesting that information about viral pathogenesis may be extractable directly from the viral genome sequence. Here we identify sequences cleaved by the SARS-CoV-2 papain-like protease (PLpro) in vitro within human MYH7 and MYH6 (two cardiac myosins linked to several cardiomyopathies), FOXP3 (an X-linked Treg cell transcription factor), ErbB4 (HER4), and vitamin-K-dependent plasma protein S (PROS1), an anticoagulation protein that prevents blood clots. Zinc inhibited the cleavage of these host sequences in vitro. Other patterns emerged from multispecies sequence alignments of the cleavage sites, which may have implications for the selection of animal models and zoonosis. SSHHPS/nsP is an example of a sequence-specific post-translational silencing mechanism

    A UTILIZAÇÃO DA IMUNOFLUORESCÊNCIA INDIRETA NO DIAGNÓSTICO DE ROTINA DA LEISHMANIOSE VISCERAL CANINA E SUAS IMPLICAÇÕES NO CONTROLE DA DOENÇA

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    Neste trabalho foram analisados, por enzyme-linked immunosorbent assay (ELISA) e imunofluorescência indireta (IFI), 101 soros caninos provenientes da Região Metropolitana de Salvador, Bahia, sendo 30 soros de cães com resultado parasitológico positivo para Leishmania chagasi em cultura esplênica e 71 soros de cães clinicamente sadios. Dez soros de cães com cultivo positivo e com resultados sorológicos concordantes ou não entre os testes ELISA e IFI foram testados pela técnica de Western-Blotting (WB). Das 30 amostras de soro com resultado positivo em cultura, o ELISA detectou 27 amostras positivas e o IFI mostrou resultado positivo em 12. Das 71 amostras de soro de cães clinicamente sadios, todas apresentaram resultados negativos no ELISA e uma apresentou resultado positivo no IFI. A sensibilidade e a especificidade foram de 90% e 100% para o ELISA e 40% e 98,6% para IFI, respectivamente. O índice de concordância Kappa entre os testes foi considerado moderado (0,53), e os resultados do WB apresentaram maior concordância com o ELISA. Este estudo demonstra a possibilidade de falha no teste IFI na detecção de cães infectados e discute a sua implicação no controle da doença em áreas endêmicas. PALAVRAS-CHAVE: Cães, ELISA, IFI, Leishmania chagasi, Western-Blotting
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