Made available in DSpace on 2016-04-26T18:12:57Z (GMT). No. of bitstreams: 1 Elvair Grossi.pdf: 23353994 bytes, checksum: 90448126b72022d459d6aeef2d4c58a6 (MD5) Previous issue date: 2013-05-20 / The present study investigates and analyzes the movies: Vidas Secas (1963), by Nelson Pereira dos Santos; Macunaíma (1969), by Joaquim Pedro de Andrade, and Auto da Compadecida (2000), by Guel Arraes, all of them based on literary narratives. Our discussion will cover elements present in the process of formation and organization of Brazilian culture, such as cannibalism, intertextuality and carnivalization. To this end, we will use the concepts of writing, dialogism and carnivalization, based on Bakhtin s work and his circle; the concept of intertextuality, the relation between "I" and the "other", from Bakhtin and Kristeva s work; and the concept of cannibalism, as elaborated by Oswald de Andrade. Assuming that every film is a cultural text and based on these theorists, we try to identify each stage of constitution of this process, using films or meshes whose texts are constituents of literary narratives: a text, a discourse or a Brazilian novel that has been transformed into an image, a film discourse and, from this theoretic axis, to analyze the presence of intertextuality, carnivalization and cannibalism in the construction of filmic text; to verify how the transposition of the literary text to the filmic text occurred, as well as the importance of dialogism, carnivalization and cannibalism as elements that structure, organize and set the unit of meaning; comparison of the literary text with the filmic text regarding to the ideas (content) and the structure. In that order, presenting the cinema as a filmic text, as a tissue of the media structured by complex discursive lines, the study organizes a corpus from three Brazilian films, of which we discuss, in the line of Metz and Bellour, the editing structures of cinematograph enunciation, the framing and the linearity, that allows the organization and understanding of the narrative of filmic text and the conversion to the literary text. In the field of aesthetics, editing and visual metaphors, we seek the theories of Eisenstein and Bazin, because we understand that in the filmic texts (Brazilian cinema) and its interaction with literary novels, language strategies (verbal signs) and visual strategies (nonverbal signs) will allow to experience the formation of our culture, taking into account their sign systems / O presente trabalho procura investigar e analisar os filmes: Vidas Secas (1963), de Nelson Pereira dos Santos; Macunaíma (1969), de Joaquim Pedro de Andrade, e Auto da Compadecida (2000), de Guel Arraes, baseados em narrativas literárias. Nossa discussão abordará elementos presentes no processo de formação e organização da cultura brasileira, tais como a antropofagia, a intertextualidade e a carnavalização. Para tal, iremos nos valer dos conceitos de escritura, dialogismo e carnavalização, fundamentados em Bakhtin e seu círculo; do conceito de intertextualidade, da relação entre o eu e o outro , a partir dos trabalhos de Bakhtin e Kristeva; e do conceito de antropofagia, conforme elaborado por Oswald de Andrade. Partindo do pressuposto de que todo filme é um texto e tomando como base esses teóricos, procuraremos identificar cada etapa da constituição desse processo, recorrendo a filmes cujos textos ou malhas são constituintes de narrativas literárias: um texto, um discurso ou um romance brasileiro que tenha sido transformado numa imagem, num discurso fílmico e, a partir desse eixo, analisar a presença da intertextualidade, carnavalização e antropofagia na construção no texto fílmico; verificar como ocorreu a transposição do texto literário para o texto fílmico, bem como a importância do dialogismo, da carnavalização e da antropofagia como elementos estruturadores, organizacionais e estabelecedores de unidade de sentido; comparação do texto literário com o texto fílmico relativamente às ideias (conteúdos) e à estruturação. Nesse intuito, apresentando o cinema como texto fílmico, como um tecido da mídia estruturado por complexas linhas discursivas, será organizado um corpus a partir de três filmes brasileiros, dos quais abordaremos, na linha de Metz e Bellour, as estruturas de montagem da enunciação cinematográfica, o enquadramento e a linearidade, que permitem a organização e entendimento da narrativa do texto fílmico e, nesse, a conversão para o literário. Já no campo da estética, da montagem e das metáforas visuais, buscamos os teóricos Eisenstein e Bazin, pois entendemos que, nos textos fílmicos (cinema brasileiro), na sua interação com os romances literários, as estratégias linguísticas (signos verbais) e as estratégias visuais (signos não verbais) permitirão experienciar a formação de nossa cultura, levando em consideração seus sistemas de signos

Among the different types of massive stars in advanced evolutionary stages is the enigmatic WN8h type. There are only a few Wolf–Rayet (WR) stars with this spectral type in our Galaxy. It has long been suggested that WN8h-type stars are the products of binary evolution that may harbor neutron stars (NS). One of the most intriguing WN8h stars is the runaway WR 124 surrounded by its magnificent nebula M1-67. We test the presence of an accreting NS companion in WR 124 using ~100 ks long observations by the Chandra X-ray observatory. The hard X-ray emission from WR 124 with a luminosity of L X ~ 1031 erg s−1 is marginally detected. We use the non-local thermodynamic equilibrium stellar atmosphere code PoWR to estimate the WR wind opacity to the X-rays. The wind of a WN8-type star is effectively opaque for X-rays, hence the low X-ray luminosity of WR 124 does not rule out the presence of an embedded compact object. We suggest that, in general, high-opacity WR winds could prevent X-ray detections of embedded NS, and be an explanation for the apparent lack of WR+NS systems.

In this thesis I have investigated the effects of invading top and intermediate consumers in a size-structured fish community, using a combination of field studies, a lake invasion experiment and smaller scale pond and aquaria experiments. The lake invasion experiment was based on introductions of an intermediate consumer, ninespine stickleback (Pungitius pungitius L.), in to allopatric populations of an omnivorous top predator, Arctic char (Salvelinus alpinus L.). The invasion experiment was performed in two tundra lakes and in two birch forest lakes to investigate the effect of climate on the invasion success. I found that the effect of sticklebacks on char was size dependent. Small char suffered reduced growth from resource competition with sticklebacks whereas the maximum size of adult char increased from the addition of a larger prey resource, stickleback. The negative effect of sticklebacks on the growth of small char suggests that sticklebacks may be a better resource competitor than char, which was also supported by the pond and aquaria experiments. The pond experiments also suggested that char were more efficient cannibals than interspecific predators on sticklebacks. Cannibalism in char may limit the recruitment of char and decrease both their predatory and competitive effect on coexisting species and thereby also promote the coexistence of char and sticklebacks. The successful invasion by sticklebacks and their subsequent increases in density suggest that the absence of sticklebacks in char lakes in this region is not caused by biotic interactions with char. Instead, it may be suggested that co-occurrence of sticklebacks and char in the region is limited by dispersal. The char – stickleback system resembles an intraguild predation system with char as the top consumer and stickleback as the intermediate consumer. The effects of the stickleback invasion is also contrasted with a field study of a northern pike (Esox lucius L.) invasion into a system with coexisting char and stickleback, where pike can be viewed as the top consumer and char as the intermediate consumer both feeding on sticklebacks. In this case pike excluded char. The identity of the invading species and the relative strength of the predatory and competitive interactions in the two contrasting systems are discussed in relation to coexistence in intraguild predation systems. I found that the identity of the invading species is of crucial importance for the response at the ecosystem level, and that the inherent size dependency of competitive and predatory interactions in fish communities is important for attaining a mechanistical understanding of the effects of invasive species in lake ecosystems.

Interspecific predation and cannibalism and associated rates of oviposition were assessed for adult female Metaseiulus occidentalis (Nesbitt) and Typhlodromus pyri Scheuten when provided non-limiting amounts of either eggs, larvae, protonymphs, or deutonymphs. Tests with all four stages of phytoseiids and larvae of Tetranychus urticae Koch were carried out at 25°C. At 15 and 12.5°C only larvae of phytoseiids and larvae of T. urticae were prey items. Predation by T. pyri was higher than M. occidentalis at 12.5 and 15°C, but more similar at 25°C. M. occidentalis did not feed appreciably on phytoseiid larvae at 15° and 12.5°C. Neither phytoseiid oviposited at 12.5°C when fed phytoseiid larvae, but T. pyri did at 15°C. We concluded that T. pyri was a more active predator at low temperatures and early-season predation on M. occidentalis immatures by T. pyri could contribute to displacement of M. occidentalis from apple orchards in western Oregon. The effects of prey species and prey density on the rates of inter- and intraspecific predation and oviposition of the two phytoseiid mite predators Metaseiulus occidentalis (Nesbitt) and Typhlodromus pyri Schueten were investigated through a series of laboratory experiments. Adult female predators were given mixed populations of phytoseiid larvae and larvae of a more preferred prey, the spider mite, Tetranychus urticae Koch, at different rates and proportions. T. pyri, more of a generalist predator, consistently showed higher rates of predation and cannibalism on phytoseiid immatures at most prey populations and proportions. Manly Preference Indices indicated that T. pyri switched to feed on phytoseiid immatures at higher population levels and proportions of T. urticae than did M. occidentalis. This ability to readily utilize phytoseiid immatures as prey indicated that maintaining both predators in a biological control program at low prey densities may require the use of active selective techniques that favour M. occidentalis. The differential impact of Zetzellia mali on the phytoseiids Metaseiulus occidentalis and Typhlodromus pyri was studied in laboratory experiments and by analysis of population data from experimental orchard plots containing either of the phytoseiid species, similar numbers of prey mites, and high or low populations of Z. mali. Five hypotheses were evaluated to explain why Z. mali had more impact on M. occidentalis in the field than on T. pyri.. Given equal opportunity, Z. mali adult females did not consume greater numbers of M. occidentalis eggs than T. pyri eggs nor did adult females of either phytoseiid species inflict greater mortality on Z. mali eggs or larvae through attack or consumption. There was no difference in the within tree association of Z. mali adult females with the eggs of either phytoseiid species nor were there differences in the way prey mites (all stages) were spatially partitioned between adult female Z. mali as compared with adults and deutonymphs of either of the two phytoseiids. The foraging area of adult female Z. mali and the oviposition locations of the two phytoseiids from both field and laboratory assessments were compared using spatial statistical procedures. M. occidentalis laid significantly more eggs in the primary foraging area of adult female Z. mali than did T. pyri. This spatial difference was the only factor tested which might explain the observed greater impact of Z. mali on M. occidentalis. Impact of these interspecific interactions and competition on the persistence of predatory mite guilds for the biological control of plant-feeding mites are discussed. / Graduation date: 1995

There are several ways in which people can relate to eating or not eating animals. This essay is focussing two main strategies: Making distances and drawing borders. Today, there are several reasons for not eating meat, including environmental reasons, individual and public health reasons, ethical reasons and more. Yet, people eat more meat than ever. According to the UN, this is a major problem. In 2006 the report Livestock’s long shadow pointed out that meat consumption was a bigger problem from an environmental point of view, than global transports, including air-traffic. At the same time, western societies are becoming both more animal friendly (when it comes to companion animals) and more animal abusive (when it comes to production animals). There seems to be a lot of empathy for animals, yet people choose to hurt them, kill them and eat them. This essay, with a feministic approach, tries to reveal what mechanisms are behind this ambigous behaviour. The findings suggest that the border line between humans and animals is blurred due to several reasons. / Att äta eller inte äta djur är en fråga som det går att förhålla sig till på olika sätt. Den här uppsatsen fokuserar på två huvudstrategier: Avståndstagande och gränsdragningar. I dag finns många anledningar till att inte äta kött, till exempel miljöskäl, hälsoskäl (såväl individuella som folkhälsomässiga), etiska skäl med flera. Ändå äter jordens befolkning mer kött än någonsin. Enligt FN är det ett stort problem. Rapporten "Livestock's long shadow" som kom ut 2006, pekar ut köttkonsumtionen som ett större miljöproblem än världens samlade transporter, inklusive flygtransporter. Samtidigt, håller västerländska samhällen på att bli allt mer djurvänliga (när det handlar om sällskapsdjur) och allt mer djurfientliga (när det handlar om så kallade produktionsdjur). Det finns uppenbarligen mycket empati för djuren, ändå väljer människor att göra dem illa,  döda dem och äta dem. Den här uppsatsen försöker ur ett feministiskt perspektiv undersöka de mekanismer som ligger bakom detta ambivalenta beteende. Resultatet tyder på att gränsen mellan människa och djur är en kulturell konstruktion som håller på att suddas ut, av flera skäl.

This dissertation concerns the epic poem Caramuru (1781) by José de Santa Rita Durão. I propose both a post-nationalist or postcolonial reading of Caramuru, as well as a pre-nationalist or historical analysis. The first part of this dissertation focuses on the form itself, particularly the genre of epic poetry to which Caramuru belongs. The title of this dissertation references Virgil’s Aeneid, while the comparisons between this and other epics focus on the conventions of epic poetry, placing Caramuru within the context of other epic poems. Traditionally, and even recently, Caramuru has consistently been compared to Luis de Camões’ Os Lusíadas. I have tried to establish a closer connection with Virgil’s Aeneid, rather than Os Lusíadas, as the model epic for Caramuru. Chapter One focuses on the topic of imitation, specifically the many similarities with the plot of Virgil’s Aeneid. Chapter Two offers a historiographical approach to how the readings of colonial texts changed over time, including a historical background of Caramuru, which was written soon after the fall of the so-called enlightened despotism of Portugal under the Marques de Pombal. The second part of this dissertation is a close reading of the text itself, and focuses on the colonial discourse present in the poem. Chapter Three is an analysis of the religious discourse in Caramuru, which reflects the preoccupations of an Augustinian monk living in the Age of Enlightenment. Chapter Four concerns the representations of Amerindian resistance in the poem, particularly of two characters who belong to the insubordinate Caeté tribe. The last chapter focuses on the issue of gender and how women are represented in Caramuru. The main woman protagonist is a Tupinambá woman who becomes a prototype for Iracema, a well-known fictional character from nineteenth-century Brazil. Santa Rita Durão was born in Brazil but lived most of his adult life in Portugal, plus 15 years in Italy. He wrote that the motivation to write this poem was his ‘love of homeland’ or nationalist sentiment, even though the nation of Brazil was yet to exist at the time he wrote Caramuru. / text

Most animals grow substantially during their lifetime and change in competitive ability, predatory capacity and their susceptibility to predation as they grow. This thesis addresses the implications of this on regulation and dynamics within populations as well as between population interactions. In size-structured populations either reproduction or maturation may be more limiting. If juveniles are competitively superior, the competitive bottleneck will be in the adults and reproduction will be limiting. Mortality will in this case result in overcompensation in juvenile biomass through increased reproduction. Compensation in biomass was demonstrated in Daphnia pulex populations subjected to size-independent mortality, where juvenile biomass did not decrease when a substantial harvest was imposed due to increase per capita fecundity. This supported that juveniles were superior competitors and that population cycles seen in Daphnia are juvenile-driven. Compensatory responses in biomass may lead to that predators facilitate eachothers existence by feeding on a common prey, a phenomenon coined emergent facilitation. In an experimental test of the mechanism behind emergent facilitation it was demonstrated that the invertebrate predator Bythotrephes longimanus was favoured by thinning of its prey Holopedium gibberum. The thinning mimicked fish predation and targeted large individuals while Bythotrephes preferrs small prey. Size dependent predation also occurs within populations, i.e. cannibalism, were large individuals feed on smaller conspecifics. Two populations of the common guppy (Poecilia reticulata) originating from different environments were demonstrated to differ in cannibalistic degree. Cannibalism was also affected by the presence of refuges and females and juveniles from one population were better adapted to structural complexity than the other. The effects of these differences in cannibalism on population regulation and dynamics were studied in long term population experiments. Both populations were regulated by cannibalism in the absence of refuges, and displayed cannibal-driven cycles with suppression of recruitment and high population variability. The presence of refuges decreased density dependence and population variability and harvesting of large females in the absence of refuges led to population extinctions in the more cannibalistic population. The less cannibalistic population had higher population biomass and stronger density-dependence in the presence of refuges. When refuges were present, cohort competition increased and cycles with short periodicity were seen. Large individuals were not only cannibals, but could successfully prey on other species. Small and large guppies were allowed to invade resident populations of Heterandria formosa. Small invaders failed while large invaders succeeded as predation from large invaders broke up the competitive bottleneck that the resident population imposed on juveniles of the invader.

abstract: Differences between males and females can evolve through a variety of mechanisms, including sexual and ecological selection. Because coloration is evolutionarily labile, sexually dichromatic species are good models for understanding the evolution of sex differences. While many jumping spiders exhibit diverse and brilliant coloration, they have been notably absent from such studies. In the genus Habronattus, females are drab and cryptic while males are brilliantly colored, displaying some of these colors to females during elaborate courtship dances. Here I test multiple hypotheses for the control and function of male color. In the field, I found that Habronattus males indiscriminately court any female they encounter (including other species), so I first examined the role that colors play in species recognition. I manipulated male colors in H. pyrrithrix and found that while they are not required for species recognition, the presence of red facial coloration improves courtship success, but only if males are courting in the sun. Because light environment affects transmission of color signals, the multi-colored displays of males may facilitate communication in variable and unpredictable environments. Because these colors can be costly to produce and maintain, they also have the potential to signal reliable information about male quality to potential female mates. I found that both red facial and green leg coloration is condition dependent in H. pyrrithrix and thus has the potential to signal quality. Yet, surprisingly, this variation in male color does not appear to be important to females. Males of many Habronattus species also exhibit conspicuous markings on the dorsal surface of their abdomens that are not present in females and are oriented away from females during courtship. In the field, I found that these markings are paired with increased leg-waving behavior in a way that resembles the pattern and behavior of wasps; this may provide protection by exploiting the aversions of predators. My data also suggest that different activity levels between the sexes have placed different selection pressures on their dorsal color patterns. Overall, these findings challenge some of the traditional ways that we think about color signaling and provide novel insights into the evolution of animal coloration. / Dissertation/Thesis / Ph.D. Biology 2012

Submitted by Luiza Helena Bueno da Silva null (bueno.luizah@gmail.com) on 2017-10-02T13:04:18Z No. of bitstreams: 1 Dissertação Luiza.pdf: 2492240 bytes, checksum: 760cbfcbde8b0aca71cdc95bd132254b (MD5) / Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-10-02T18:31:27Z (GMT) No. of bitstreams: 1 silva_lhb_me_rcla.pdf: 2492240 bytes, checksum: 760cbfcbde8b0aca71cdc95bd132254b (MD5) / Made available in DSpace on 2017-10-02T18:31:27Z (GMT). No. of bitstreams: 1 silva_lhb_me_rcla.pdf: 2492240 bytes, checksum: 760cbfcbde8b0aca71cdc95bd132254b (MD5) Previous issue date: 2017-08-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A presença de cadáveres no interior dos ninhos dos insetos sociais pode propiciar a contaminação com patógenos e prejudicar a integridade da colônia. O comportamento higiênico frente a cadáveres é imprescindível na manutenção da homeostase do ninho, mas em cupins ainda é pouco conhecido. Assim, o objetivo do presente trabalho foi estudar o comportamento higiênico diante de cadáveres de diferentes origens em três espécies de cupins com distintos tipos de nidificação. O cupim de madeira seca Cryptotermes brevis vive no interior do próprio alimento, o cupim Cornitermes cumulans constrói ninhos epígeos e o cupim Coptotermes gestroi é subterrâneo e constrói ninhos polidômicos. Diferentes bioensaios foram realizados com colônias de C. brevis e C. cumulans, nas quais foram introduzidos cadáveres de operários da mesma colônia, de outra colônia e de outra espécie. Adicionalmente, bioensaios foram realizados com subcolônias de C. gestroi (grupos de 300 operários e 15 soldados), nas quais foram inseridos cadáveres de operários e soldados da mesma colônia, de outra colônia e de outra espécie mortos recentemente e há 24 horas. Os bioensaios foram filmados e as respostas comportamentais dos indivíduos próximos aos cadáveres foram registradas. O repertório comportamental de C. brevis diante de cadáveres incluiu antenação, agonismo, alarme, recuo, grooming e consumo dos mesmos. Ninfas e falsos-operários de C. brevis consumiram os cadáveres, independentemente, da origem dos mesmos, mas evitaram a ingestão das partes quitinosas da cabeça. Nesta espécie, o consumo de cadáveres, além de desempenhar função higiênica, parece ser uma estratégia de aquisição de nitrogênio e água. O casal real das colônias de C. brevis observadas não participou do comportamento higiênico. O repertório comportamental de C. cumulans incluiu diferentes atividades, tais como: antenação, agonismo, alarme, recuo, grooming, deposição de material fecal, enterro com solo e transporte do cadáver para o ninho. Nesta espécie, corpos de origem interespecífica e intercolonial foram cobertos com solo após grooming. Corpos de companheiros de ninho foram enterrados (60% das repetições), carregados para o ninho (30%) ou ignorados após serem submetidos ao grooming (10%), o que indica uma plasticidade comportamental em C. cumulans. Em subcolônias de C. gestroi o repertório comportamental incluiu atividades como: antenação, recuo, grooming, agonismo, alarme, deposição de solo e consumo integral ou parcial do cadáver. Soldados de grupos de C. gestroi não consumiram ou enterraram cadáveres. Corpos de operários de diferentes origens foram discriminados por subcolônias de C. gestroi, o que não aconteceu com cadáveres de soldados com tempo de post-mortem maior. Cadáveres de cupins de outras espécies e de outras colônias foram enterrados após grooming por grupos de C. gestroi, porém companheiros de ninho foram preferencialmente canibalizados. O caráter higiênico do comportamento de grooming em cadáveres juntamente com o isolamento físico por meio do enterro dos mesmos com solo colabora para a não dispersão de patógenos entre membros da colônia. Os resultados do presente trabalho mostram que os cupins realizam o comportamento higiênico em cadáveres de térmitas de diferentes origens, contudo este processo foi mais simples em C. brevis, cupim com nidificação do tipo “uma peça”. Nos cupins “múltiplas peças” tais como C. gestroi e C. cumulans, o comportamento higiênico foi mais complexo, com recrutamento de indivíduos, mostrando que o manejo de cadáveres é essencial para o desenvolvimento e homeostase destes ninhos. / The presence of dead individuals inside nests of social insects can be a risk of contamination with pathogens and damage the integrity of the colony. The hygienic behavior towards corpses is essential in maintaining nest homeostasis, but in termites it is still little known. Thus, the objective of the present study was to observe the hygienic behavior towards corpses from different origins in three species of termites with distinct types of nesting. The drywood termite Cryptotermes brevis lives inside its own food, Cornitermes cumulans builds mound nests and Coptotermes gestroi is a subterranean termite that builds polydomous nests. Different bioassays were performed with colonies of C. brevis and C. cumulans, in which corpses of workers of termites from the same colony, from another colony and from another species were introduced. Additionally, bioassays of subcolonies of C.gestroi were performed in which corpses of workers and soldiers from the same colony, from another colony and from another species freshly dead and dead for 24 hours were introduced. The bioassays were recorded and the behavioral responses from the different species were registered. The results showed that the behavioral repertoire of C. brevis towards corpses included: antenation, aggression, alarm, retreat, grooming and consumption. Nymphs and pseudergates of C. brevis consumed the corpses independently of their origin, but they avoided the chitinous parts of the head. In this species, consumption of dead individuals, besides performing a hygienic function, seems to be a strategy of nitrogen and water acquisition. The royal couple of C. brevis colonies observed did not participate of the hygienic behavior. The behavioral repertoire of C. cumulans towards corpses included activities, such as: antenation, agression, alarm, retreat, grooming, deposition of fecal material, entombment and transport of corpse to the nest. In this species, inter-specific and inter-colonial corpses were covered with soil after being groomed. Nestmate corpses were entombed (60% of replications), transported to the nest (30%) or ignored after being submitted to grooming (10%), which indicates the behavioral plasticity of the C. cumulans species. In subcolonies of C. gestroi the behavioral repertoire included activities such as: antenation, retreat, grooming, aggression, alarm, deposition of soil, integral or partial consumption of corpses. Soldiers of C. gestroi subcolonies never consumed or buried corpses. However, corpses of workers from different origins were discriminated by C. gestroi subcolonies, which did not occurred with corpses of soldiers with longer period of post-mortem. Termite corpses from another species or from another colony were buried after being groomed by C. gestroi groups, but nestmate corpses were preferably cannibalized. The hygienic character of grooming behavior in corpses along with the physical isolation through entombment with soil contributes to the non-dispersion of pathogens among colony members. The results of the present study indicate that termites perform hygienic behavior in termite corpses from different origins, however, this process was less elaborate in C. brevis, one-piece nesting termite. In multiple-pieces nesting termites, such as C. gestroi and C. cumulans, the hygienic behavior was more complex, with recruitment of individuals, showing that the management of corpses is essential for the development and homeostasis of the termite nests.

abstract: The most advanced social insects, the eusocial insects, form often large societies in which there is reproductive division of labor, queens and workers, have overlapping generations, and cooperative brood care where daughter workers remain in the nest with their queen mother and care for their siblings. The eusocial insects are composed of representative species of bees and wasps, and all species of ants and termites. Much is known about their organizational structure, but remains to be discovered. The success of social insects is dependent upon cooperative behavior and adaptive strategies shaped by natural selection that respond to internal or external conditions. The objective of my research was to investigate specific mechanisms that have helped shaped the structure of division of labor observed in social insect colonies, including age polyethism and nutrition, and phenomena known to increase colony survival such as egg cannibalism. I developed various Ordinary Differential Equation (ODE) models in which I applied dynamical, bifurcation, and sensitivity analysis to carefully study and visualize biological outcomes in social organisms to answer questions regarding the conditions under which a colony can survive. First, I investigated how the population and evolutionary dynamics of egg cannibalism and division of labor can promote colony survival. I then introduced a model of social conflict behavior to study the inclusion of different response functions that explore the benefits of cannibalistic behavior and how it contributes to age polyethism, the change in behavior of workers as they age, and its biological relevance. Finally, I introduced a model to investigate the importance of pollen nutritional status in a honeybee colony, how it affects population growth and influences division of labor within the worker caste. My results first reveal that both cannibalism and division of labor are adaptive strategies that increase the size of the worker population, and therefore, the persistence of the colony. I show the importance of food collection, consumption, and processing rates to promote good colony nutrition leading to the coexistence of brood and adult workers. Lastly, I show how taking into account seasonality for pollen collection improves the prediction of long term consequences. / Dissertation/Thesis / Doctoral Dissertation Applied Mathematics 2018