The Euler characteristic as a topological marker for outbreaks in vector-borne disease

Abstract. Epidemic outbreaks represent a significant concern for the current state of global health, particularly in Brazil, the epicentre of several vector-borne disease outbreaks and where epidemic control is still a challenge for the scientific community. Data science techniques applied to epidemics are usually made via standard statistical and modelling approaches, which do not always lead to reli- able predictions, especially when the data lacks a piece of reliable surveillance information needed for precise parameter estimation. In particular, dengue out- breaks reported over the past years raise concerns for global health care, and thus novel data-driven methods are necessary to predict the emergence of out- breaks. In this work, we propose a parameter-free approach based on geometric and topological techniques, which extracts geometrical and topological invariants as opposed to statistical summaries used in established methods. Specifically, our procedure generates a time-varying network from a time-series of new epidemic cases based on synthetic time-series and real dengue data across several dis- tricts of Recife, the fourth-largest urban area in Brazil. Subsequently, we use the Euler characteristic (EC) to extract key topological invariant of the epidemic time-varying network and we finally compared the results with the effective reproduction number (Rt) for each data set. Our results unveil a strong cor- relation between epidemic outbreaks and the EC. In fact, sudden changes in the EC curve preceding and/or during an epidemic period emerge as a warn- ing sign for an outbreak in the synthetic data, the EC transitions occur close to the periods of epidemic transitions, which is also corroborated. In the real dengue data, where data is intrinsically noise, the EC seems to show a better sign-to-noise ratio once compared to Rt. In analogy with later studies on noisy data by using EC in positron emission tomography scans, the EC estimates the number of regions with high connectivity in the epidemic network and thus has potential to be a signature of the emergence of an epidemic state. Our results open the door to the development of alternative/complementary topological and geometrical data-driven methods to characterise vector-borne disease outbreaks, specially when the conventional epidemic surveillance methods are not effective in a scenario of extreme noise and lack of robustness in the data

Produtividade da videira de vinho cv. Syrah submetida a diferentes doses de nitrogênio e potássio aplicadas via fertirrigação.

O objetivo deste estudo foi avaliar a produção da videira de vinho cv. Syrah submetida a diferentes doses de nitrogênio e potássio aplicados via fertirrigação

Influência do volume da calda na eficácia in vitro do Diflubenzuron a imaturos de Stomoxys calcitrans.

Explosões populacionais da mosca-dos-estábulos (Stomoxys calcitrans) associadas a usinas sucroalcooleiras tornaram-se um problema sem precedentes em alguns estados, com graves impactos econômicos, sociais e ambientais. Eliminação e adequado manejo dos subprodutos e resíduos orgânicos constituem a principal estratégia de prevenção destes surtos, contudo o controle químico torna-se necessário em situações críticas. O presente estudo objetivou avaliar in vitro a in4uência do volume da calda inseticida na e0cácia de um produto à base de di4ubenzuron 25% a imaturos desta mosca

Eficácia in vitro da aplicação superficial x homogeneizada do Diflubenzuron a imaturos de Stomoxys calcitrans.

A mosca-dos-estábulos (Stomoxys calcitrans) tornou-se um sério problema em diversas localidades do país devido à ocorrência de surtos associados a resíduos orgânicos produzidos em usinas sucroalcooleiras. A eliminação e/ou o adequado manejo dos sítios de reprodução da mosca (matéria vegetal em decomposição) consiste na principal estratégia de controle do parasito e prevenção de surtos; entretanto, a aplicação de produtos inseticidas nos sítios de desenvolvimento larvar pode ser uma medida necessária, dependendo da situação. O presente estudo objetivou avaliar in vitro a e1cácia do di3ubenzuron 25% aplicado super1cialmente, em comparação com sua posterior homogeneização ao meio de desenvolvimento larvar. Bioensaios foram realizados em potes plásticos transparentes (250 g), contendo 50 g de meio de criação: cana triturada (330 g), farelo de soja (125 g), farinha de carne (50 g) e água (250 ml)

Using discrete Ricci curvatures to infer COVID-19 epidemic network fragility and systemic risk

The damage of the novel Coronavirus disease (COVID-19) is reaching unprecedented scales. There are numerous classical epidemiology models trying to quantify epidemiology metrics. Usually, to forecast epidemics, classical approaches need parameter estimations, such as the contagion rate or the basic reproduction number. Here, we propose a data-driven, parameter-free, geometric approach to access the emergence of a pandemic state by studying the Forman-Ricci and Ollivier- Ricci network curvatures. Discrete Ollivier-Ricci curvature has been used successfully to forecast risk in nancial networks and we suggest that those results can provide analogous results for COVID-19 epidemic time-series. We rst compute both curvatures in a toy-model of epidemic time-series with delays, which allows us to create epidemic networks. We also compared our results to classical network metrics. By doing so, we are able to verify that the Ollivier-Ricci and Forman-Ricci curvatures can be a parameter-free estimate for identifying a pandemic state in the simulated epidemic. On this basis, we then compute both Forman-Ricci and Ollivier-Ricci curvatures for real epidemic networks built from COVID-19 epidemic time-series available at the World Health Organization (WHO). This approach allow us to detect early warning signs of the emergence of the pandemic. The advantage of our method lies in providing an early geometrical data marker for the pandemic state, regardless of parameter estimation and stochastic modelling. This work opens the possibility of using discrete geometry to study epidemic networks. Keywords: COVID-19, SARS2, Forman-Ricci Curvature, Ollivier-Ricci curvature, Epidemiology, Topologi- cal Data Analysi

Biologia de Anastrepha fraterculus (Diptera: Tephritidae) em frutos de Campomanesia xanthocarpa.

O objetivo do presente trabalho foi avaliar, em condições controladas, os parâmetros biológicos de A. fraterculus em frutos de guabiroba Campomanesia xanthocarpa