Homofilia por tópicos em uma rede social online

Orientador: André SantanchèDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Entender a dinâmica de interações sociais é crucial para o entendimento questões que envolvem o comportamento humano. O surgimento de mídias sociais online, tal como Facebook e Twitter, possibilitou o acesso a dados de relacionamentos de pessoas em larga escala. Essas redes são orientadas à informação, com seus usuários compartilhando e consumindo informação. Nesta dissertação, estamos interessados na presença de homofilia por tópicos em uma rede social. Especificamente, nós exploramos como as conexões entre indivíduos estão ligadas com a sua similaridade por tópicos, i.e., a sua proximidade em consideração com os diferentes tipos de conteúdo que circulam pela rede. Para fazê-lo, representamos usuários utilizando as informações de suas mensagens. Nossos resultados demonstram que usuários, na média, estão conectados com usuários similares a eles e que interações mais fortes estão relacionadas com uma alta similaridade por tópicos. Nós também verificamos que, quando se considera apenas usuários dentro de um tópico, a homofilia se manifesta diferentemente de acordo com o tópico. Nós acreditamos que esta pesquisa, além de fornecer uma maneira de aferir similaridade por tópicos, aumenta as evidências de homofilia entre indivíduos, contribuindo para um melhor entendimento de como sistemas sociais complexos são estruturadosAbstract: Understanding the dynamics of social interactions is crucial to address questions involving human behavior. The emergence of online social medias, such as Facebook and Twitter, has enabled the access to data of people relationships at a large scale. These networks are information oriented, with users sharing and consuming information. In this dissertation, we are interested in the presence of topical homophily in an online social network. Specifically, we explore how individuals connections are related to their topical similarity, i.e., their proximity regarding the different kinds of content that are shared in the network. To do so, we represent users using the information of their messages. Our results show that users, on average, are connected with users which are similar to them and that stronger interactions are related to a high topical similarity. We also verified that, when considering only users inside a topic, homophily manifests differently according to the topic. We believe that this research, besides providing a way to assess the topical similarity of users, deepens the evidence of homophily among individuals, contributing to a better understanding of how complex social systems are structuredMestradoCiência da ComputaçãoMestre em Ciência da Computação1629113, 1461658CAPE

Dynamics of heuristics selection for cooperative behaviour

Situations involving cooperative behaviour are widespread among animals and humans alike. Game theory and evolutionary dynamics have provided the theoretical and computational grounds to understand what are the mechanisms that allow for such cooperation. Studies in this area usually take into consideration different behavioural strategies and investigate how they can be fixed in the population under evolving rules. However, how those strategies emerged from basic evolutionary mechanisms continues to be not fully understood. To address this issue, here we study the emergence of cooperative strategies through a model of heuristics selection based on evolutionary algorithms. In the proposed model, agents interact with other players according to a heuristic specified by their genetic code and reproduce -- at a longer time scale -- proportionally to their fitness. We show that the system can evolve to cooperative regimes for low mutation rates through heuristics selection while increasing the mutation decreases the level of cooperation. Our analysis of possible strategies shows that reciprocity and punishment are the main ingredients for cooperation to emerge, being conditional cooperation the more frequent strategy. Additionally, we show that if in addition to behavioural rules, genetic relatedness is included, then kinship plays a relevant role. Our results illustrate that our evolutionary heuristics model is a generic and powerful tool to study the evolution of cooperative behaviour.Comment: 22 pages and 23 figures, including the supplementary information. Submitted for publicatio

Strategic and Selfless Interactions: a study of human behaviour

Los seres humanos son animales únicos, cooperando en una escala sin par en cualquier otra especie. Construimos sociedades compuestas de individuos no emparentados, y resultados empíricos nos han demostrado que las personas tienen preferencias sociales y pueden estar dispuestas a tomar acciones costosas que beneficien a otros. Por otro lado, los seres humanos también compiten entre ellos mismos, lo que en ocasiones conlleva consecuencias negativas como la sobreutilización de recursos naturales. Sin embargo, la competición entre agentes económicos subyace el funcionamiento adecuado de los mercados, y su destabilización -- tal como en una distribución desbalanceada de poder de mercado -- puede ser dañina a la eficiencia comercial. Por consiguiente, analizar cómo las personas cooperan y compiten es de importancia primordial para el entendimiento del comportamiento humano, especialmente al considerar los desafíos inminentes que amenazan el bienestar futuro de nuestras sociedades.En esta tesis, se presentan trabajos analizando el comportamiento de las personas en dilemas sociales -- situaciones en las cuales decisiones egoístas discrepan del optimo social -- y en otros escenarios estratégicos. Utilizando el framework de la teoría de juegos, sus interacciones tienen lugar en juegos abstrayendo estas situaciones. Específicamente, realizamos experimentos conductuales en los cuales las personas participaron en juegos adaptados de recursos comunes, de bienes públicos y otros juegos hechos a medida. Además, con la intención de comprender la existencia de la cooperación en humanos, proponemos un enfoque teórico para modelar su evolución a través de una dinámica de selección de heurísticas.Empezamos presentando los fundamentos teóricos y empíricos en los que se basa esta tesis, a saber, la teoría de juegos, la economía experimental, la ciencia de redes y la evolución de la cooperación. Posteriormente, ilustramos los aspectos prácticos de la realización de experimentos mediante implementaciones de software.Para comprender el comportamiento de las personas en problemas de acción colectiva -- como la mitigación del cambio climático, que requiere un nivel global de coordinación y cooperación -- realizamos juegos de bienes públicos y recursos comunes entre participantes chinos y españoles. Los resultados obtenidos proporcionan algunas ideas sobre las variaciones y universalidades de las respuestas de las personas en estos escenarios.En esta línea, durante los últimos años, las personas e instituciones están cada vez más preocupadas por los temas sociales y ambientales. Sin embargo, las contribuciones en estos escenarios requieren un nivel sustancial de altruismo por parte de los agentes que tienen que tomar decisiones costosas. Realizamos dos experimentos para comprender los factores que impulsan dichas decisiones en dos situaciones de relevancia contemporánea: las donaciones benéficas y las inversiones socialmente responsables. Sus resultados indican que el encuadre y otras características sociodemográficas están asociadas significativamente con decisiones prosociales y altruistas.Además, también hemos analizado el comportamiento de las personas en un escenario competitivo y complejo en el cual los sujetos participaron como intermediarios en experimentos de formación de precios. Lo hacemos a través de un experimento que implementa en redes complejas una generalización del juego de negociación. Nuestros hallazgos indican efectos significativos de la topología de la red tanto en resultados experimentales como también en modelos teóricos basados en el comportamiento observado.Por último, exponemos un trabajo teórico que intenta comprender el surgimiento de la cooperación a través de un enfoque novedoso para estudiar la evolución de estrategias en poblaciones estructuradas. Esto se logra modelando las decisiones de los agentes como resultados de heurísticas, siendo estas heurísticas seleccionadas mediante un proceso inspirado en los algoritmos evolutivos. Nuestros análisis muestran que, cuando estos agentes tienen memoria de sus interacciones anteriores, las estrategias cooperativas prosperarán. Sin embargo, esas estrategias funcionarán de acuerdo con diferentes heurísticas según la información que tomen en consideración.<br /

Topical Alignment in Online Social Systems

Understanding the dynamics of social interactions is crucial to comprehend human behavior. The emergence of online social media has enabled access to data regarding people relationships at a large scale. Twitter, specifically, is an information oriented network, with users sharing and consuming information. In this work, we study whether users tend to be in contact with people interested in similar topics, i.e., if they are topically aligned. To do so, we propose an approach based on the use of hashtags to extract information topics from Twitter messages and model users' interests. Our results show that, on average, users are connected with other users similar to them. Furthermore, we show that topical alignment provides interesting information that can eventually allow inferring users' connectivity. Our work, besides providing a way to assess the topical similarity of users, quantifies topical alignment among individuals, contributing to a better understanding of how complex social systems are structured

Effect of network topology and node centrality on trading.

Funder: Intesa Sanpaolo Innovation CenterGlobal supply networks in agriculture, manufacturing, and services are a defining feature of the modern world. The efficiency and the distribution of surpluses across different parts of these networks depend on the choices of intermediaries. This paper conducts price formation experiments with human subjects located in large complex networks to develop a better understanding of the principles governing behavior. Our first experimental finding is that prices are larger and that trade is significantly less efficient in small-world networks as compared to random networks. Our second experimental finding is that location within a network is not an important determinant of pricing. An examination of the price dynamics suggests that traders on cheapest-and hence active-paths raise prices while those off these paths lower them. We construct an agent-based model (ABM) that embodies this rule of thumb. Simulations of this ABM yield macroscopic patterns consistent with the experimental findings. Finally, we extrapolate the ABM on to significantly larger random and small-world networks and find that network topology remains a key determinant of pricing and efficiency

Isolation and Antimicrobial Resistance of Escherichia coli and Salmonella enterica subsp. enterica (O:6,8) in Broiler Chickens

Background: The third largest poultry flock in Northeast Brazil is located in Ceará State. Some pathogens are commonly disseminated in broiler chicken flocks, such as the bacteria from the Enterobacteriaceae family. Among these, some strains of Escherichia coli are frequently associated with different pathological manifestations in domestic animals, while bacteria from the genus Salmonella are considered the most frequent enteric pathogens reported causing foodborne infections in humans. Therefore, this study aimed to evaluate the prevalence and antimicrobial resistance of Salmonella sp. and Escherichia coli strains isolated from broiler chickens in the Metropolitan Region of Fortaleza city, Brazil.Materials, Methods & Results: Samples were collected from July-2014 to March-2015 in ten broiler chicken farms located in the Metropolitan Region of Fortaleza city, Brazil, with birds in pre-slaughter age. From each farm, 100 individual cloacal swabs were randomly collected from broilers independent of clinical status. Distinct methodologies were used in order to provide optimal isolation conditions for both the bacterial species. For Escherichia coli, the methodology consisted in enrichment with BHI broth, plating in EMB agar and biochemical identification, after which some isolates were maintained in nutrient agar for antimicrobial resistance evaluation. For the isolation of Salmonella sp., a standard method was used with pre-enrichment, selective enrichment, selective plating and biochemical identification steps. Antimicrobial susceptibility test (AST) was performed with disk diffusion technique and the following antibiotics were tested: ampicillin, ceftiofur, ciprofloxacin, trimethoprim-sulfamethoxazole, polymyxin B, gentamycin, cloranfenicol, tetracycline, azithromycin and fosfomycin. According to the methodology used, 95.9% of samples were positive for Escherichia coli and the most frequent resistance was to trimethoprim-sulfamethoxazole. Salmonella sp. was isolated from 0.2% of the samples, which were identified as the serotype Salmonella enterica subsp. enterica O:6,8. Both isolates presented the same antimicrobial resistance profile, which were resistant to six, out of ten tested antibiotics (trimethoprim-sulfamethoxazole, tetracycline, ciprofloxacin, azithromycin, chloramphenicol and ceftiofur).Discussion: The low prevalence of Salmonella observed in this study have also been reported by other studies performed in poultry farms in Ceará State, which suggests a good status for this pathogen in the local industry, however further efforts in order to eradicate this pathogen must be applied. The salmonella serotype detected in this study is rarely reported in the literature, especially from the poultry industry. In Brazil, the use of tetracyclines, quinolones and penicillins as feed additives or growth promoters is prohibited; however, a high resistance to drugs from these groups was detected. In addition, multidrug resistant E. coli isolates presented more elevated rates than other studies reported in the literature with antibiotics commonly used in the poultry industry and this may indicate an excessive use of these drugs in the production routine. These results should serve as a warning for surveillance programs to evaluate the incidence of these microorganisms as well as their antimicrobial resistance rates, which may be an important tool for control and prevention in meat poultry production

DOMESTIC VIOLENCE (AGAINST WOMEN) IN BRAZIL IN PANDEMIC TIMES (COVID-19)

A pandemia da Covid-19 (Corona Virus Disease 2019), causada pelo corona vírus (SARS-CoV-2) já registra casos em quase todo o mundo. A Covid-19 é uma doença respiratória de alto potencial de contágio. Diante desse quadro de ameaça à saúde global, governos têm adotado diversas medidas, dentre elas o isolamento social, apontado pela Organização Mundial da Saúde (OMS) como uma das estratégias mais eficazes na contenção da propagação viral. O isolamento consiste na manutenção das pessoas em suas residências. Porém, enquanto para alguns o isolamento representa proteção diante da Covid-19, para outras populações tal situação se configura como ameaça, como nos casos de violência doméstica. Tal tipo de violência se configura como um fenômeno complexo que pode atingir diferentes populações (crianças, mulheres, idosos). Em razão disso, no presente trabalho discutiremos sobre a violência que atinge as mulheres. Autoridades especializadas têm alertado para o aumento no número de casos de violência doméstica durante a pandemia. O objetivo do presente trabalho é discutir estratégias de enfrentamento à violência contra a mulher em situações de isolamento social por conta da pandemia. Discute-se desde a atuação conjunta de órgãos que visem assegurar a integridade física e psicológica, até possíveis contribuições da Análise do Comportamento para tais estratégias, reforçando o compromisso político do (a) analista do comportamento diante de questões sociais relevantes. Esperamos que as discussões levantadas no presente trabalho possam auxiliar no planejamento de medidas protetivas que, se eficazes, permaneçam após a pandemia.Palavras-chave: Análise do Comportamento; Violência Doméstica; Pandemia; Covid-19.The pandemic of COVID-19 (Corona Virus Disease 2019), caused by the corona virus - (SARS-CoV-2) is already registering cases almost all over the world. COVID-19 is a respiratory disease with a high potential for contagion. Faced with this situation of threat to global health, governments have adopted several measures, including social isolation, pointed out by the World Health Organization (WHO) as one of the most effective strategies to contain viral spread. Isolation consists of keeping people in their homes. However, while for some isolation represents protection from COVID-19, for other populations this situation is a threat, as in cases of domestic violence. This type of violence is configured as a complex phenomenon that can affect different populations (children, women, the elderly). As a result of this, we will discuss about the violence that affects women. Specialized authorities have warned of an increase in the number of cases of domestic violence during the pandemic. The objective of the present work is to discuss strategies to face violence against women in situations of social isolation due to the pandemic. It is discussed since joint action of institutions that aim to ensure physical and psychological integrity, until possible contributions of Behavior Analysis to such strategies, reinforcing the behavior analyst's political commitment to relevant social issues. We hope that the discussions raised in the present work can assist in planning protective measures that, if effective, remain after the pandemic.Keywords: Behavior Analysis; Domestic violence; Pandemic; COVID-19.

Aspectos médicos sobre os tumores ovarianos de Borderline: condições patológicas

The objective of this study is to expose the main concepts about borderline ovarian tumors and their pathological aspects. And, as secondary objectives, to evaluate the diagnostic measures, prognoses and treatment of these tumors, in addition to tracing the epidemiological profile of the affected patients. A review of articles was carried out in the Medical Literature Analysis and Retrievel System Online (MEDLINE), Scientific Electronic Library Online (SciELO), Latin American and Caribbean Literature in Health Sciences (LILACS) and PubMed databases, with the following Descriptors in Health Sciences (DeCS): Tumor; Borderline ovarian tumor; Revision. Selecting articles between the periods of 1996 to 2023, in English, Portuguese and Spanish. In summary, early histological diagnosis and assessment of disease staging are essential for a favorable prognosis against the disease, in addition to adequate surgical therapy. Observational and surgical studies are necessary for the improvement of techniques and the evolution of medical management against borderline tumors.El objetivo de este estudio es exponer los principales conceptos sobre los tumores de ovario borderline y sus aspectos patológicos. Y, como objetivos secundarios, evaluar las medidas diagnósticas, pronóstico y tratamiento de estos tumores, además de trazar el perfil epidemiológico de los pacientes afectados. Se realizó una revisión de artículos en las bases de datos Medical Literature Analysis and Retrievel System Online (MEDLINE), Scientific Electronic Library Online (SciELO), Latin American and Caribbean Literature in Health Sciences (LILACS) y PubMed, con los siguientes Descriptores en Ciencias de la Salud (DeCS): Tumor; Tumor de ovario borderline; Revisión. Selección de artículos entre los períodos de 1996 a 2023, en inglés, portugués y español. En resumen, el diagnóstico histológico temprano y la evaluación de la estadificación de la enfermedad son fundamentales para un pronóstico favorable de la enfermedad, además de una adecuada terapia quirúrgica. Los estudios observacionales y quirúrgicos son necesarios para la mejora de las técnicas y la evolución del manejo médico frente a los tumores borderline.Objetiva-se, neste estudo, expor os principais conceitos acerca dos tumores ovarianos de Borderlinee seus aspectos patológicos. E, como objetivos secundários, avaliar as medidas de diagnóstico, prognósticos e tratamento desses tumores, além de traçar o perfil epidemiológico das pacientes acometidas.&nbsp;Foi realizada uma revisão de artigos nas bases de dados Medical Literature Analysis and Retrievel System Online (MEDLINE), Scientific Electronic Library Online (SciELO), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) e PubMed, com os seguintes Descritores em Ciências da Saúde (DeCS): Tumor; Tumor borderline de ovário; Revisão. Selecionando artigos entre os períodos de 1996 a 2023, nos idiomas Inglês, Português e Espanhol. Em síntese, o diagnóstico histológico precoce e a avaliação do estadiamento da doença são fundamentais para o prognóstico favorável contra a doença, além da terapêutica cirúrgica adequada. Estudos observacionais e cirúrgicos são necessários para o aprimoramento das técnicas e evolução do manejo médico contra o tumore de Borderline.&nbsp

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio