Magda da Silva Peixoto

Estimating the Xenobiotics Mixtures Toxicity on Aquatic Organisms: The Use of \(\alpha \)-level of the Fuzzy Number

Agricultural practices that use various xenobiotics can contaminate surface water and groundwater with xenobiotics mixtures concentrations which cause serious risks to water quality and to the health of aquatic organisms that inhabit them. Xenobiotics in water when present as mixtures can exacerbate or reduce the toxic effects in aquatic organisms, when compared to the toxic effects of each individual component concentrations of the xenobiotics mixture. The objective of this study is to develop a mathematical method using \(\alpha \)-level of the fuzzy numbers with less accounts and simpler calculations to sort ecotoxicological effects in aquatic organisms of xenobiotics mixtures concentrations occurring in water, classifying them into antagonistic, additive or synergistic and also establishing the magnitude of the effects of concentrations of mixtures. The proposed method in this paper using fuzzy numbers can be suggested in protocols established by regulatory agencies to classify ecotoxicological effects of xenobiotics mixtures in water.

A study on the dynamics and control of the soybean aphid

This paper uses a methodology based in Fuzzy Sets Theory in order to describe the interaction between the prey, Aphis glycines (Hemiptera: Aphididae) - the soybean aphid, and its predator, Orius insidiosus (Hemiptera: Anthocoridae) and to propose a biological control and a chemical control for soybean aphid. Economic thresholds were already developed for this pest. The model includes biotic (predator) and abiotic (temperature) factors, which affect the soybean aphid population dynamics.

Um sistema fuzzy do tipo presa-predador: Aphis glycines x Orius insidiosus

Esse trabalho descreve uma metodologia baseada na Teoria dos Conjuntos Fuzzy e usa um sistema baseado em regras fuzzy para estudar a interacao entre a presa, Aphis glycines (pulgao da soja) e seu predador, Orius insidiosus (percevejo). Nosso principal objetivo e a tomada de decisao no controle dessa presa.