Invasões biológicas são uma das maiores ameaças à biodiversidade mundial. O estabelecimento de espécies exóticas, principalmente de insetos, em vários países ocorreu por meio da utilização de controle biológico, quando se introduz uma espécie exótica para o controle de outra. Em alguns casos, por diferentes motivos, espécies introduzidas com este objetivo acabaram se tornando invasoras. O besouro coprófago Digitonthophagus gazella é um destes exemplos. O objetivo desta tese foi avaliar o impacto de D. gazella sobre a abundância, diversidade e turnover de uma comunidade de besouros coprófagos nativos no Brasil. A comunidade foi amostrada semanalmente, e no mesmo local, desde novembro de 1989, através de armadilha luminosa, obtendo-se dados até novembro de 2015. A espécie exótica invadiu a área após quatro anos do início das coletas, tendo-se no presente estudo 22 anos de coletas semanais dessa espécie exótica introduzida. Na comunidade já havia outra espécie coprófaga exótica presente, Labarrus pseudolividus, que possui hábito residente de nidificação. A invasão por D. gazella modificou substancialmente a comunidade local. A abundância, diversidade e riqueza da comunidade nativa apresentavam tendência de aumento antes, passando a diminuir após a invasão. As espécies com o mesmo hábito de nidificação de D. gazella (escavador) não mostraram sinais de recuperação dos impactos, com todos os índices apresentando decréscimo contínuo desde a invasão, principalmente do turnover, tamanho populacional e riqueza de espécies. Espécies residentes, exibindo hábito similar a L. pseudolividus, foram capazes de recuperar o status após alguns anos, mantendo-se mais estáveis a partir do ano 15. Quando analisado o turnover da comunidade atual, ou seja, espécies nativas e exóticas, observou-se que toda a dinâmica da comunidade foi mantida pelas espécies exóticas. A partir da diminuição da abundância de D. gazella houve aumento na de L. pseudolividus, levando a uma aparente estabilidade na diversidade e turnover, a despeito do comportamento oposto observado na comunidade nativa. A partir da invasão por D. gazella, variáveis climáticas, fatores responsáveis principais pela característica da comunidade, passaram a execer menor influência. / Biological invasions are one of the major threats to the global biodiversity. The use of exotic species as agents of biological control is one way to contribute to invasions. In some cases, the introduced species became invasive. The tunneler dung beetle (DB) Digothophagus gazella is a good example. Released in many countries, including Brazil, to improve dung pad removal, the species quickly spread to new ones, where it is considered as an invasive species. The objective of this thesis was to evaluate impacts of D. gazella on the abundance, alfa-diversity and turnover of a native DB community in Brazil. Another exotic DB species, the dweller Labarrus pseudolividus, was present in the study area. The community was sampled weekly, at the same location, from November 1989 until November 2015 using a black light trap. The exotic species was first recorded four years after the beginning of sampling. The invasion by D. gazella changed significantly the native community. Abundance, diversity and richness were increasing during the first years, however they all decreased since the invasion. Species with the same nesting behavior of D. gazella (tunneler) were not able to recover from the impacts, with turnover, abundance and species richness continuously decreasing after the invasion. Dweller species on the contrary were able to partially recovery after some years, rebound its abundance and turnover since year 15. Results from the turnover analysis of the current community, which is native and exotic, showed that it has been influenced by both exotic species. Following the decrease in abundance of D. gazella and native species, L. pseudolividus was able to increase its abundance, leading to stabilization of the turnover despite the opposite observed in the native community. Since the invasion by D. gazella, weather variables became less important on the changes observed.

Cells adhere to each other and to the extracellular matrix (ECM) through protein molecules on the surface of the cells. The breaking and forming of adhesive bonds, a process critical in cancer invasion and metastasis, can be influenced by the mutation of cancer cells. Several molecules have been reported to play a crucial role in cellular adhesion and proliferation, and eventually in cancer progression, with TGF-β being one of the most important. In this thesis, we propose a general framework to model cancer cells movement and aggregation, in response to nonlocal social interactions (that is, attraction towards neighbours that are far away, repulsion from those that are near by, and alignment with neighbours at intermediate distances), as well as other molecules' effect, e.g., TGF-β. We develop nonlocal mathematical models describing cancer invasion and metastasis as a result of integrin-controlled cell-cell adhesion and cell-matrix adhesion, for two cancer cell populations with different levels of mutation. The models consist of nonlinear partial differential equations, describing the dynamics of cancer cells and TGF-β dynamics, coupled with nonlinear ordinary differential equations describing the ECM and integrins dynamics. We study our models analytically and numerically, and we demostrate a wide range of spatiotemporal patterns. We investigate the effect of mutation and TGF-β concentration on the speed on cancer spread, as well as the effect of nonlocal interactions on cancer cells' speed and turning behaviour.

Ces dernières années ont vu le développement du commerce international entraînant une accélération des mouvements intercontinentaux d'espèces. Ces multiples introductions sont à l'origine de nombreux cas d'invasion, où les espèces s'établissent et se dispersent. Dans le nouvel environnement, étudier les facteurs liés à la niche écologique permet de comprendre comment se déroule l'établissement des espèces introduites au sein de la communauté d'espèces résidentes. L'hypothèse de la niche vide, qui prédit que l'invasion est possible car un espace vide existe au sein des niches écologiques de la communauté résidente, est un des facteurs facilitants de nombreux cas d'invasion. Par ailleurs, la stratégie d'exploitation de la ressource par l'espèce invasive au sein de la niche écologique peut aussi expliquer la propension d'une espèce à envahir ou non le nouvel environnement. L'objectif de cette thèse est d'explorer l'importance de ces hypothèses dans le succès invasif, au travers de l'exemple de Drosophila suzukii. Introduite en 2008 en Europe et aux Etats-Unis, cette espèce a envahi chacun des continents en moins de 7 ans. Elle est la seule espèce européenne de drosophiles capable de pondre à l'intérieur de fruits sains omniprésents, au sein d'une niche écologique vide de tout compétiteur. Elle est à l'origine de gros problèmes pour la culture de fruits cultivés et se retrouve être l'un des ravageurs majeurs en production de fruits rouges. Mieux comprendre son invasion, sa niche écologique et sa stratégie de sélection d'habitat permet de mieux lutter contre l'insecte, notamment par des méthodes permettant de perturber la localisation des fruits dans l'environnement. Cet aspect appliqué est aussi un objectif important de cette thèse CIFRE, financée pour optimiser la lutte par piégeage massif / In the last few decades, the development of international trade has seen resulting in an acceleration of intercontinental movements of species. These multiple introductions are the cause of many cases of invasion, where species are established and spread. In the new environment, studying factors related to the ecological niche help understanding what happens during the establishment of introduced species within the community resident species. The “empty niche hypothesis”, which predicted that the invasion is possible because a gap exists in the ecological niches of the resident community, is one of the facilitating factors of many cases of invasion. In addition, the strategy of utilization of the resource by the invasive species in the ecological niche may also explain the propensity of a species to invade or not the new environment. The objective of this thesis is to explore the significance of these assumptions in the invasive success, through the example of Drosophila suzukii. Introduced in 2008 in Europe and the US, this species has invaded every continent in less than 7 years. It is the only European species of fruit flies that can lay eggs inside healthy fruits, which are omnipresent, in an ecological niche free of any competitor. It is the cause of dreadful issues for grown fruit and is one of the major pests in production of berries. Better understand its invasion, its ecological niche and habitat selection strategy help better fighting the insect, including methods to disrupt the location of fruit in the environment. This applied context is also an important aspect of this thesis, funded also to optimize the fight by mass trapping

O sucesso da gestação depende da adequada comunicação materno-fetal, que em algumas espécies têm um contato mais íntimo devido à capacidade migratória de populações de células trofoblásticas. Nos bovinos esse mecanismo é realizado pelas células trofoblásticas gigantes (CTGs), com invasão limitada até a lâmina basal do epitélio materno. Apesar dessa leve invasão das CTGs, é possível encontrar células fetais circulantes no sangue periférico da vaca gestante, levando ao microquimerismo fetal. Além de toda uma sinalização local e sistêmica e mudanças conformacionais, a migração das CTGs também é dependente da tolerância imunológica do epitélio materno que possui uma baixa expressão de MHC de classe I. Em contrapartida, o trofoblasto expressa MHC de classe Ib para impedir a ativação das células natural killers uterinas (uNK) contra ele mesmo. Neste contexto, o objetivo desse trabalho foi estudar a ocorrência e contribuir para o entendimento dos mecanismos da migração celular na placenta bovina, com marcadores exclusivos do cromossomo Y e de um modelo de clone transgênico expressando a proteína GFP. A hipótese testada foi que o microquimerismo fetal observado mediante a detecção do gene TSPY no sangue periférico da vaca gestante de embrião macho, e de GFP nos tecidos placentários maternos, associado à expressão de MHC classe 1b (Qa2) na interface materno-fetal. Para tanto, 153 embriões produzidos por fertilização in vitro (FIV) foram transferidos, resultando em 34 embriões machos e 31 fêmeas no dia 62 de gestação, quando foi realizada a coleta de sangue periférico da receptora. Dentre estas gestações, foram selecionadas de 25 machos, 4 fêmeas e 5 perdas gestacionais (confirmadas no D39 por ultrassonografia) para detecção de TSPY. Também foram produzidas gestações de clones transgênicos, expressando GFP com 30, 60 e 90 dias que foram utilizadas para a detecção de mRNA e a proteína GFP. Nas gestações de FIV 60% dos embriões machos, 50% das fêmeas e 40% das perdas gestacionais foram positivos para TSPY. A detecção de TSPY nas gestações de fêmeas possivelmente é resultante da persistência do microquimerismo de gestações anteriores. Nas gestações de clones transgênicos, observou-se a presença de mRNA e proteína GFP no endométrio, também indicando migração nesta região ou o transporte da GFP, e outros conteúdos do trofoblasto, para o epitélio materno. Nos placentônios, usando anticorpo anti-GFP pode-se ver a marcação positiva tanto no trofoblasto como no epitélio materno, possivelmente decorrente de liberação das CTGs no estroma endometrial após a fusão. As CTGs, quando em formação sincicial, têm a sua expressão de GFP diminuída, o que também foi observado, utilizando-se anticorpo anti-Qa2 (antígeno murino para MHC classe Ib). O epitélio materno e o trofoblástico também foram marcados para Qa2. Mediante as técnicas utilizadas, observamos que o microquimerismo pôde ser identificado nas gestações analisadas com o uso dos marcadores TSPY no sangue e o GFP nos tecidos placentários maternos. Este estudo mostra que na placenta bovina ocorre uma migração de células fetais além do epitélio materno e abre novas perspectivas para estudos das características da interação materno-fetal ainda pouco explorada nos bovinos. / The pregnancy success depends of adequate materno-fetal communication, that in some species are have a more intimate contact due migratory capacity of trophoblastic cells populations. In bovines, this mechanism is realized by trophoblast giant cells (TGC) with limited invasion until basal lamina of maternal epithelium. Besides this light invasion of TGCs, is possible to encounter circulate fetal cells in peripheral blood of pregnant cow, leading to fetal microchimerism. Beyond local and systemic sinalization and conformational changes, TGC migration is also dependent of immunologic tolerance of maternal epithelium that possess a downregulation of classe I MHC. In complement, the trophoblast express classe Ib MHC to inhibit natural killers cells activation. In this context, the objective of this work was to study the occurrence and contribute for knowledge cellular migration mechanisms in bovine palcenta, with Y-specific markers and a model of transgenic clone expressing GFP. The tested hypothesis was that fetal microchimerism observed by detection od TSPY gene in peripheral blood of cow pregnant of male embryo, and of GFP in maternal placental tissues associated by expression of class Ib MHC (Qa2) in materno-fetal interface. For this, 153 embryos produced by in vitro fertilization (IVF) were trasnfered, resulting in 34 male embryos and 31 female in day 62 of pregnancy, when recipient peripheral blood was collected. Among these pregnancies, 25 males, 4 females and 5 pregnancy losses (confirmed at 39 days of pregnancy by ultrassonography) was selected for TSPY detection. Also were produced pregnancies of transgenic cloned, embryos expressing GFP, with 30, 60 and 90 days of pregnancy that utilized for GFP mRNA and protein detection. In IVF pregnancies, 60% of male embryos, 50% of females and 40% of pregnancy losses were positive for TSPY. The detection of TSPY in female pregnancies possible is resultant of persistence of microchimerism of anterior pregnancies. In transgenic cloned pregnancies, was observed presence of GFP mRNA and protein in endometrium, also indicating migration in this region or GFP transport, and another trophoblast content, to maternal epithelium. In placentomes, using anti-GFP antibody, could be observed positive immunolabeling in trophoblast and maternal epithelium, possible due CTGs liberation in endometrial stroma after fusion. The CTGs, in syncytium formation, have a downregulation of GFP, that also be observed, utilizing anti-Qa2 antibody (murine antigen of classe Ib MHC). The maternal and trophoblastic epithelium also was Qa2 immunolabed. By utilized techniques, microchimerism could be indentified in analyzed pregnancies with use of markers for TSPY in maternal blood and GFP in maternal placental tissues. This study show that in bovine placenta occurs fetal cell migration further maternal epithelium and show new perspectives for studies of materno-fetal interaction characteristics until under explored in bovines.

O presente trabalho teve o objetivo de elaborar um modelo de análise do jogo de futebol baseado em uma referência dinâmica de descrição do jogo. A elaboração deste modelo foi feita com base no modelo semântico de Lamas (2012) e na linguagem de descrição dos eventos de Seabra (2010). A partir da proposta de Lamas (2012) foi elaborado um modelo com maior resolução conceitual inspirado na categorização de tarefas de Bayer (1986), específico ao jogo de futebol. Depois disso, este modelo com maior resolução conceitual foi adaptado à linguagem de descrição dos eventos de Seabra (2010). Com o modelo adaptado foram elaboradas categorias de segmentos (classes de dinâmicas) a partir da decomposição do jogo em segmentos elementares e posterior reagrupamento destes em classes maiores que representam as transições entre as fases do modelo. A frequência de ocorrência destes segmentos foi o objeto de análise. Foram criadas três tipos de comparações entre classes a partir das frequências: classes principais, subclasses de penetração e subclasses de penetração que resultam em finalização. A aplicação do modelo na mesma unidade amostral de Seabra (2010) demonstrou que as classes de comparação são eficientes na discriminação da forma de jogar das equipes. Entretanto, o modelo final apresenta ainda muitas simplificações que diminuem seu potencial descritivo. Em virtude disto, ainda é necessário aprimora-lo para potencializar a descrição dos eventos jogo / The aim of this study was to create model soccer analysis based dynamic model. The preparation this model was based on semantic model of Lamas (2012) and events description language of Seabra (2010). A model with greater resolution inspired by the conceptual categorization tasks of Bayer (1986), specific to soccer game was elaborated from semantic model of Lamas (2012). After that, this conceptual model with higher resolution was adapted to events description language of Seabra (2010). From the adapted model, categories of segments (dynamic classes) were created from the decomposition of the game in elementary segments and subsequent reunification of these segments into larger segments classes that represent the transitions between the stages of the model. The frequency of these class was the central point of analyze. It was create three types of comparisons from class\' frequencies: main classes, penetration subclasses and finalization subclasses penetration. The application gave strong indications that the classes should be efficient in predicting the form of the teams playing. However, the final model has many simplifications that reduce its descriptive potential. For this reason, it is still necessary to improve the model to enhance the description of the game events

Nos cerrados brasileiros, várias gramíneas africanas foram introduzidas, tornando-se invasoras e ameaçando a biodiversidade nativa. É, portanto, imprescindível a elaboração de medidas para seu controle. O objetivo deste estudo foi avaliar a eficiência e o custo de diferentes métodos para o controle das gramíneas invasoras Urochloa decumbens e Melinis minutiflora, em unidades de conservação de proteção ao cerrado. O trabalho foi desenvolvido no Cerrado Péde- Gigante e na Estação Ecológica de Itirapina (SP, Brasil), onde foram selecionadas seis manchas com dominância de U. decumbens e seis com M. minutiflora. Em cada mancha, aplicou-se um bloco randômico com os tratamentos: corte raso, uma vez (CRI, nov/2007) e duas vezes (CRII, nov/2007 e mar/2008), corte e revolvimento do solo, uma vez (CRSI, nov/2007) e duas vezes (CRSII, nov/2007 e mar/2008), sombreamento (SOM), abafamento (ABF), estes aplicados em julho/2007, permanecendo cobertos respectivamente com tela de nylon e lona até mar/2008. Ao final do experimento (jul/2008), a biomassa das parcelas foi cortada e separada em categorias (graminóides nativas, U. decumbens, M. minutiflora, dicotiledôneas). As análises basearam-se em testes de permutação. Posteriormente, foram calculados os custos de cada tratamento com mão-de-obra, materiais, ferramentas, transporte e descarte para o manejo das áreas. Para U. decumbens, os tratamentos mais eficientes para reduzir sua biomassa foram ABF, CRII e CRSII, sendo o ABF economicamente viável apenas para manejo de pequenas infestações; para áreas maiores, os tratamentos de corte mostram uma melhor relação benefício/custo. Para M. minutiflora, ABF, CRII, CRSII e CRSI são eficientes em reduzir sua biomassa e o tratamento CRSI é o que possui maior relação benefício/custo, portanto, o mais viável para o controle de desta gramínea. / Several African grasses introduced in the Brazilian savannas for cattle feeding became invasive, and now they severely threaten the native biodiversity. It is, therefore, fundamental to look for effective methods to control them. The objective of this study was to evaluate the efficiency and cost of different management techniques to control the invasive grasses Urochloa decumbens and Melinis minutiflora. The study was conducted in the Cerrado Pé-de-Gigante and Itirapina Ecological Station (SP, Brazil). Six plots dominated by U. decumbens and six by M. minutiflora were selected and a random block design was applied including the treatments: clipping once ( CRI, nov/2007) and twice (CRII, nov/2007 and mar/2008), clipping and soil digging once (CRSI, nov/2007) and twice (CRSII, nov/2007 and mar/2008), shading (SOM), mugging (ABF), being the last two applied in July/2007 and remained covered until mar/2008, respectively with nylon mesh and canvas. At the end of the experiment (jul/2008), all biomass in the blocks was cut and separated into categories (native grasses, U. decumbens, M. minutiflora and dicotyledons). The analyses were based on permutation tests. The cost of each treatment was calculated taking into account materials, tools, labor, transportation and discharge. The most effective treatments to reduce U. decumbens biomass were ABF, CRII and CRSII, being ABF economically viable only for small patches; the double-clipping treatments showed best benefit/cost value in large areas. The treatments ABF, CRII, CRSI and CRSII were effective in reducing M. minutiflora biomass, being CRSI the one which showed a best benefit/cost value; therefore, clipping and digging is the best way to control that grass.

The invasibility, or susceptibility of an ecosystem to biological invasion is influenced by changes in biotic and abiotic resistance often due to shifts in disturbance regime. The magnitude of invasive propagule pressure interacts with an ecosystem's invasibility to determine the extent of a biological invasion. I examined how propagule pressure, forest community structure and disturbance interact to influence the invasibility of temperate Pacific Northwest forests by the newly-invasive grass, Brachypodium sylvaticum. My goal was to identify which of these factors is most instrumental in enabling the shift from establishment to population growth in B. sylvaticum at the edge of its expanding range. Both observational and experimental studies were employed to identify the many ecological components of this problem. Ecological sampling methods were used to identify trends in B. sylvaticum habitat preference and signs of habitat disturbance. In addition, an experimental study was performed to test the effects of soil and vegetation disturbance on B. sylvaticum seedling propagation. I found that while soil disturbance did not have a significant effect on seedling propagation, vegetation disturbance was implicated in B. sylvaticum spread. Higher propagule pressure and coniferous forest type were also strong predictors of increased B. sylvaticum seedling propagation and survival within established sites. My study demonstrates how propagule pressure and plant community dynamics interact to shift the invasibility of Pacific Northwest forests and facilitate the transition from establishment to spread in the invasion of B. sylvaticum.

Biological invasions of non-native species are one of the most serious factors threatening global biodiversity. Their negative impacts are particularly evident in the case of freshwater ecosystems and native crayfish populations that live there. Generally, the higher dominance of non-native crayfish species over the native species is relatively well known, but the interactions between non-native crayfish species are significantly less investigated. Although their distribution is increasingly more important and it is obvious that non-native crayfish species will dominate in European waters. However, it is not yet clear which of these crayfish will be more successful. The aim of this diploma thesis was to create a literature review on the topic of interspecific interactions in crayfish with emphasis on native and non-native crayfish species occurring in Europe. The experimental part of the thesis was focused on the comparison of direct interactions and competition for shelter between the widespread spiny-cheek crayfish Faxonius limosus (Rafinesque, 1817) and the newly increasingly occurring marbled crayfish Procambarus virginalis Lyko, 2017. These species are becoming increasingly common in the European wild, but about their mutual direct interactions and competition is largely unknown. During agonistic interactions the marbled crayfish won in significantly more fights than the spiny-cheek crayfish in the absence as well as presence of the shelter. The marbled crayfish established a significantly greater dominance over the females of the spiny-cheek crayfish in the absence and in the presence of shelter, but not over the males. It is also important to say that the presence of the shelter reduces the number of fights and their total duration. There was no significant difference in dominance established by occupation of shelter between the marbled crayfish and the spiny-cheek crayfish. Still, thanks to its aggressiveness, marbled crayfish is able to compete with other non-native species or displace them from freshwater ecosystems.

The mountain pine beetle (MPB, Dendroctonus ponderosae), a tree-killing bark beetle, has historically been part of the normal disturbance regime in lodgepole pine (Pinus contorta) forests. In recent years, warm winters and summers have allowed MPB populations to achieve synchronous emergence and successful attacks, resulting in widespread population outbreaks and resultant tree mortality across western North America. We develop an age-structured forest demographic model that incorporates temperature-dependent MPB infestations: the Susceptible-Infested-Juvenile (SIJ) model. Stability of fixed points is analyzed as a function of population growth rates, and indicates the existence of periodic outbreaks that intensify as growth rates increase. We devise analytical methods to predict outbreak severity and duration as well as outbreak return time. To assess the vulnerability of natural resources to climate change, we develop a thermally-driven mechanistic model to predict MPB population growth rates using a distributional model of beetle phenology in conjunction with criteria for successful tree colonization. The model uses projected daily minimum and maximum temperatures for the years 2025 to 2085 generated by three separate global climate models. Growth rates are calculated each year for an area defined by latitude range 42° N to 49° N and longitude range 108° W to 117° W on a Cartesian grid of approximately 4km resolution. Using these growth rates, we analyze how the optimal thermal window for beetle development is changing with respect to elevation as a result of climate change induced warming. We also use our combined model to evaluate if thermal regimes exist that would promote life cycle bivoltinism and discuss how yearly growth rates would change as a result. Outbreaks of MPB are largely driven by host tree stand demographics and spatial effects of beetle dispersal. We augment the SIJ model to account for the spatial effects of MPB dispersal throughout a forest landscape by coupling it with a Gaussian redistribution kernel. The new model generates a train of sustained solitary waves of infestation that move through a forest with constant speed. We convert the resulting integrodifference equation into a partial differential equation and search for travelling wave solutions. The resulting differential equation provides predictions of the shape of an outbreak wave profile and of peak infestation as functions of wave speed, which can be calculated analytically. These results culminate in the derivation of an explicit formula for predicting the severity of an outbreak based on the net reproductive rate of MPB and host searching efficiency.

Human activities worldwide have altered nature in ways that create new combinations of species and environmental processes. To understand so-called "novel ecosystems" it is important to consider both the natural and the societal factors that shape them, and how those factors are interconnected or "coupled." We used such an approach to explore options for managing a non-native invasive frog, the coqui, which has become established on the island of Hawaii and threatens to spread to other parts of the state. The nighttime calls of the coqui create a nuisance for property owners when populations become dense enough, as often occurs in Hawaii where the frogs have no natural enemies. Humans have tried various ways to eliminate coqui on the island of Hawaii with little success. Therefore we studied how property owners cope with their presence, both through management practices and psychological coping strategies. We also examined results of those efforts. People whose properties had more frogs were more likely to take action to reduce their numbers, but also attitudes toward the coqui were less negative when people had grown used to having to share their properties with the frogs. For those who cannot cope psychologically, we found it would be possible to manage properties to reduce densities but only when leaf litter and low shrubs were completely removed from near a home. Information campaigns about managing coqui should be different when targeting people that already host frogs and those that do not.