Redes comportamentais e a organização da divisão de trabalho em Odontomachus Chelifer (Latreille, 1802) (Formicidae: Ponerinae)

Resumo: A divisão de trabalho é considerada um dos fatores responsáveis pelo sucesso evolutivo de insetos sociais, porém pouco se sabe sobre como redes comportamentais dentro da colônia afetam os padrões observados de organização social. O objetivo deste trabalho é analisar a organização da divisão de trabalho em Odontomachus chelifer através de repertórios comportamentais individuais e redes complexas. Três colônias com rainha (N=07, 30 e 60 operárias) foram acondicionadas em laboratório com condições ambientais controladas. Cada formiga foi marcada individualmente e observada pelo método de amostragem em varredura por 10 horas em cada 10 minutos (N=5917). Deste modo, foram levantados os atos comportamentais e através destes a posição espacial e da mandíbula de cada indivíduo, índices de divisão de trabalho (DOL) e redes de associações comportamentais (N=29484). Os resultados indicam que não existe especialização significativa entre as operárias, mas associações comportamentais provavelmente importantes na divisão de trabalho e a existência de padrões de aninhamento. As colônias de Odontomachus chelifer possuem divisão de trabalho generalista com algumas operárias potencialmente sendo indivíduos-chave

Comportamento complexo da atividade individual de insetos em ambientes delimitados

Orientadora : Prof. Dr. Marcio Roberto PieCoorientador : Prof. Dr. Ricardo Luiz VianaTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Ciências Biológicas (Entomologia). Defesa: Curitiba, 30/06/2016Inclui referências : f.37-42;55-58;70-72;92-101Área de concentração : EntomologiaResumo: Como podemos mensurar a complexidade do comportamento animal? Nesta tese utilizo análises de recorrência (i.e. Plots de recorrência e RQA - Recurrence quantification analysis), descrição de comportamentos de movimento, incluindo o uso de modelagem matemática, para a compreensão do comportamento complexo de atividade individual de insetos em ambiente delimitados. Embora o estudo de insetos como sistemas complexos, em especial insetos com algum nível de organização social (colônias, agregações), seja promissor, a influência do comportamento individual na emergência de padrões auto organizados é pouco estudada. Estruturei a tese em três capítulos distintos. O primeiro capítulo desta tese é sobre o uso de análises de recorrência no estudo comportamental da atividade de insetos, sua aplicação e significância na interpretação de sinais estocásticos e determinísticos no comportamento animal. Comparei o padrão de atividade de três espécies de formigas, assim como de uma espécie solitária/gregária (Tenebrio molitor) para explorar a influência de níveis diferentes de complexidade social. Esta foi a primeira aplicação de análises de recorrência no estudo do comportamento de atividade, e uma das primeiras aplicações do método para fenômenos biológicos. Nossos resultados demonstram o potencial de análises de recorrência na análise de padrões de comportamento complexo. O segundo capítulo introduz a pouco conhecida espécie de vespa Perreyia flavipes, onde descrevemos pela primeira vez na literatura sobre o seu comportamento. Perreyia flavipes apresenta comportamentos interessantes em um intervalo curto de vida (36 hrs), tal como tanatose e cuidado maternal primitivo. Atos comportamentais são descritos e comparados entre os sexos, e suas possíveis funções são discutidos. O terceiro capítulo enfoca no comportamento das larvas de Perreyia flavipes, que apresentam comportamento gregário, se movimentando em grupos e de modo aparentemente coordenado. Neste capítulo abordo a influência de espaços delimitados no comportamento individual de P. flavipes através de dados experimentais e modelagem matemática. Espero que o presente estudo auxilie nos avanços dentro da área de mensuramento de testes empíricos de sistemas complexos em contextos biológicos. Palavras-chave: Sistemas complexos, tracking de movimento, comportamento de insetos, dinâmica de movimentosAbstract: How could we measure the complexity of animal behavior? In this thesis I use recurrence analysis (i.e. recurrence plots and RQA - Recurrence quantification analysis), motion behavior description, including mathematical modelling to understand the complex behavior of individual activity of insects in boundaries spaces. Although the study of insects as complex systems, specially, insects with some degree of social organization (e.g. eusocial colonies, aggregations) is promising, the influence of individual behavior in the emergence of self-organized patterns is not well studied. I structured the thesis in three distinct chapters. The first chapter of this thesis is about the use of analysis of recurrences in the behavioral study of insect activity, its application and significance in the interpretation of stochastic and deterministic signals in animal behavior. I compared the activity patterns of three ant species, as well as a solitary/gregarious species (Flour beetle), to explore varying levels of social complexity. This was the first application of recurrence analysis to the study of animal activity, and one of the first applications to biological phenomena. In particular, our results underscore the potential of recurrence analyses in the analysis of complex behavioral patterns. The second chapter introduces the not well studied species of sawfly Perreyia flavipes, where we describe for the first time in the literature its behavior. Perreyia flavipes presents interesting behaviors in a short life span (36 hours), such as thanatosis and primitive maternal care. Individual behavioral acts are described and compared among sexes, and their potential functions are discussed. The third chapter focuses on the behavior of Perreyia flavipes larvae, which have gregarious behavior, moving in groups and apparently coordinated mode. In this chapter, I study the influence of boundaries spaces in the movement behavior of individual larvae by experimental data and statistical modelling. I hope that the present study helps in the advances in the area of behavioral measurement of empirical experiments of complex systems. Keywords: Complex systems, movement tracking, behavior of insects, movement dynamics

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Recurrence analysis of ant activity patterns

<div><p>In this study, we used recurrence quantification analysis (RQA) and recurrence plots (RPs) to compare the movement activity of individual workers of three ant species, as well as a gregarious beetle species. RQA and RPs quantify the number and duration of recurrences of a dynamical system, including a detailed quantification of signals that could be stochastic, deterministic, or both. First, we found substantial differences between the activity dynamics of beetles and ants, with the results suggesting that the beetles have quasi-periodic dynamics and the ants do not. Second, workers from different ant species varied with respect to their dynamics, presenting degrees of predictability as well as stochastic signals. Finally, differences were found among minor and major caste of the same (dimorphic) ant species. Our results underscore the potential of RQA and RPs in the analysis of complex behavioral patterns, as well as in general inferences on animal behavior and other biological phenomena.</p></div

Comparison of the RQA measures: Recurrence rate (RR), determinism (DET), entropy (ENT), laminarity (LAM) and trapping time (TT) between the species.

<p>Comparison of the RQA measures: Recurrence rate (RR), determinism (DET), entropy (ENT), laminarity (LAM) and trapping time (TT) between the species.</p

Recurrence plots (RP’s) of the time series.

<p>Each species had a characteristic recurrence plot pattern, here demonstrate by representative time series (approximately 2400 points; equivalent to 7200 seconds) with measures near the median RQA values from the replicates. The species are <i>Gnamptogenys striatula</i> (a), <i>Linepithema micans</i> (b), <i>Pheidole rudigenis</i> minor (c) and major subcaste (d), and <i>Tenebrio molitor</i> (e). In the RP’s, white dot are maximum distance and black dots are minimum. Estimated parameters: Dimension = 3, Time delay = 3 and the Threshold values were variable with each time series and are signalled in each RP.</p

RQA percentage measures of the species (columns) compared with each respective surrogate data series (_surr).

<p>Recurrence rate (RR), determinism (DET), entropy (ENT), laminarity (TT) and trapping time (TT) of the original and surrogate data (_surr).</p

The experimental setup.

<p>Measurements, disposition view of the light spots, camera and the tracking arena (a). Video frame of an ant (<i>Linepithema micans</i>) in the arena during the tracking, the black line corresponds to the movement of the ant (b). Final tracking coordinates (x,y) of 2400 frames extracted from a time series (<i>Linepithema micans</i>), the grey dashed lines are the coordinates obtained (c).</p