La construction des routes avec des techniques d'enrobage à chaud (T=160 °C) implique une consommation d'énergie fossile et des rejets de gaz à effet de serre importants. Une production plus écologique du bitume nécessite de diminuer les températures d'enrobage en conservant les propriétés mécaniques des enrobés ainsi obtenus. Le développement de techniques permettant de réduire les températures est donc un enjeu majeur de l'industrie routière. Dans ce travail, nous avons joué à la fois sur la composition et le procédé pour moduler les propriétés du bitume et atteindre l’objectif fixé.Nous avons décomposé le bitume en ses différentes fractions en utilisant des techniques de séparation asphaltènes/maltènes à l'aide d'un alcane (pentane et heptane). Nous avons formulé des bitumes à différentes proportions et natures d'asphaltènes en introduisant des protocoles de préparation originaux. A l’aide de techniques de caractérisation variées telles que la rhéologie, la diffusion des rayons X ou encore des techniques de microscopies et d'analyses thermiques, nous avons déterminéles rôles des différentes fractions du bitume. Nous avons ainsi montré l'impact important des asphaltènes, mais également des fractions que nous avons qualifiées « d'intermédiaires », sur les comportements rhéologiques. Enfin, nous avons élaboré des objets coeur-écorce, composés d’une écorce rigide, non collante, riche en asphaltènes et d’un coeur mou, riche en maltènes. Ces objets sont particulièrement intéressants pour le transport du bitume à température ambiante. / The classic manufacture of hot mix asphalt for road construction is associated with a high consumption of fossil fuels and a high level of emissions of greenhouse gases into the atmosphere. A cleaner production of bitumen requires lowering the manufacturing temperature of these products without impoverishing their level of mechanical performances. The development of technologies that enable temperature reduction had thus become a major objective in the field of road engineering. In this work, we are playing on both composition and process in order to control the final properties of the material and propose an interesting way to reduce temperature during transportation. We have been interested in the different fractions composing the bitumen. We have there by employed a separation technique with alkane (heptane and pentane) to segregate the maltenes and asphaltenes. We could therefore realize diverse reconstituted bitumen using original protocols. Using various characterization techniques (such as rheology, X-ray scattering, optic, electronic and atomic force microscopy, infrared spectroscopy, thermal analysis...), we get insight into the effect of asphaltenes content and nature on bitumen properties. Our results show the huge impact of asphaltenes and other fractions called "intermediate fractions" on bitumen rheological properties. Finally, we propose an innovative processing of bitumen via the elaboration of core/shell objects composed of a rigid, nonsticky and asphaltenes-rich corona and a soft maltenes-rich core. These objects are very interesting for transporting bitumen at ambient temperature.

Os meliponíneos (Apidae, Meliponini) são insetos com organização altamente eussocial, formando colônias com população que varia de centenas a milhares de indivíduos. Em suas colônias, as operárias distribuem suas atividades conforme a faixa etária. As mais jovens são responsáveis pelos cuidados da cria, trabalhos com a cera e cerume, construção e aprovisionamento de células. As mais velhas ocupam as posições de receptoras e desidratadoras de néctar, guardas e forrageiras. As colônias de meliponíneos são perenes. Para isso, as operárias forrageiam continuamente em busca dos recursos florais e estocam grande quantidade de pólen e néctar em potes de alimento. A atividade de voo das campeiras está relacionada aos fatores meteorológicos como: temperatura, intensidade luminosa, umidade relativa, precipitação pluviométrica e vento. Neste estudo investigamos a influência dos fatores meteorológicos (temperatura e umidade relativa), bem como da disponibilidade de recursos florais na coleta de pólen e néctar das operárias de Melipona quadrifasciata Lep. Além disso, analisamos os tipos polínicos encontrados nas corbículas das abelhas forrageiras e nos potes de mel. Cinco colônias foram instaladas em um meliponário no Parque das Neblinas, em Mogi das Cruzes (23º4452S/46º0946W). Observações e amostragem nestas colônias foram realizadas mensalmente durante um ano, entre outubro de 2009 e setembro de 2010. As entradas das abelhas foram monitoradas durante dois dias consecutivos, durante 5 minutos por hora, entre 05:30 e 16:30h, totalizando 1430 observações. Foram extraídas 133 amostras de pólen das corbículas e 29 dos potes de mel. O pólen foi analisado a fresco. Os picos de coleta de pólen e néctar ocorrem após as 08:00h. Os resultados mostram que temperaturas amenas são ideais para o forrageamento de M. quadrifasciata. Nos potes de mel foram encontrados 25 tipos polínicos, sendo os mais frequentes Eucalyptus, Melastomataceae, Myrcia e Solanaceae. Nas corbículas foram encontrados 8 tipos polínicos, sendo os mais frequentes os mesmos encontrados no mel. Apesar do caráter generalista de M. quadrifasciata, foi verificado que esta espécie possui preferências por determinadas fontes de plantas melíferas. O conhecimento sobre aspectos de atividades de voo e utilização de recursos florais por diferentes espécies de abelhas são importantes para a manutenção e preservação das mesmas, além de atender a programas de manejo de polinizadores, reflorestamento e restauração ambiental. / The stingless bees (Apidae, Meliponini) are insects with high eusocial organization, composing colonies of hundred or thousands individuals. The tasks inside the nest are divided according to the age of the workers. The younger are responsible to the care of the brood, work with wax, construction and supply of the cells. The older receive and dehydrate the nectar, act as guards and foragers. The stingless bees colonies are perennial. For this, the workers forage continuously in search of floral resources and store large amount of pollen and nectar on the food pots. Flight activity of foragers is correlated with climatic factors as temperature, light intensity, relative humidity, rainfall and wind. In this study we investigated the influence of climate conditions (temperature and relative humidity), as well as the available floral resources on the pattern of pollen and nectar collection by workers of Melipona quadrifasciata Lep. in natural conditions. Furthermore, we analyzed the pollen types found on the corbiculae of the forager bees and honey pots. Five colonies were displayed in an meliponario at the Parque das Neblinas, in Mogi das Cruzes (23º4452S/46º0946W). The flight activity of the bees was observed monthly between October 2009 and September 2010. The entries of the bees into the nest were recorded along two consecutive days, during 5 minutes per hour, between 5:30am to 4:30pm, which corresponded to 1430 observations. A total of 133 samples were extracted from corbiculae and 29 of honey pots. The pollen were prepared fresh. The peaks of pollen and nectar collection occurred after 8am. The results show that mild temperatures is ideal for foraging of M. quadrifasciata. In the honey pots 25 pollen types were found, being the most frequent Eucalyptus, Melastomataceae, Solanaceae and Myrcia. In the corbiculae eight pollen types were found, being the most frequent the same as found in the honey. Despite been considered generalist, M. quadrifasciata shows preferences for certain sources of melittophilous plants. The knowledge about the flight activity and use of floral resources by the different bee species are important to the maintenance of them, since we can understand their needs and manage them as pollinators or in environmental restoration program.

The foraging activity of day-active bees often rely on flower availability, light intensity and temperature. However, some bees developed a nocturnal habit and fly during the dusk, dawn and night. We still do not know how these bees cope with environmental factors, especially dimmer light levels, to explore flower earlier than their diurnal relatives. Given that typical bee apposition compound eyes work better in brighter environments and function in their limits in dim-light conditions, we can expect a larger dependence of light intensity for nocturnal groups. Nocturnal and crepuscular bees are frequent visitors of cambuci (Campomanesia phaea, Myrtaceae) in southeastern Brazil. We aimed to investigate how light intensity affects flower visitation of cambuci by nocturnal and crepuscular bees, also controlling for other environmental factors. We counted visits per minute along 30 nights/twilights in 33 cambuci trees from a commercial orchard, measuring the following environmental variables: light intensity, flower availability, temperature, air relative humidity and wind speed. Light intensity is the only variable that explained flower visitation of nocturnal bees in cambuci, which peaks at intermediate light levels that occur around 30 minutes before sunrise. The minimum light intensity threshold to bees start flying is of 0.00024 cd/m2, the first recorded value for nocturnal and crepuscular bees finding flowers in an agro-forest context. Our results highlight for the first time how nocturnal bees rely on light to explore resources and show that the bees light-dependent foraging activity is not always linear, as postulated by previous theoretic models. This is the first step to understand how nocturnal bees react to environmental factors. Our findings also bring concerns about possible negative effects of light pollution at night for cambuci-crepuscular bees interaction / O forrageio de abelhas geralmente depende de disponibilidade de flores, intensidade de luz e temperatura. Contudo, algumas abelhas desenvolveram hábitos noturnos e voam durante os crepúsculos e a noite. Não se sabe como essas abelhas lidam com os fatores ambientais, especialmente os reduzidos níveis de luminosidade. Dado que os olhos compostos de aposição de abelhas funcionam melhor em maiores luminosidades, espera-se uma maior dependência da luz para os grupos noturnos. Abelhas noturnas e crepusculares são visitantes frequentes do cambuci (Campomanesia phaea, Myrtaceae) no sudeste do Brasil. Nosso objetivo foi investigar como a intensidade de luz afeta a visitação floral do cambuci por abelhas noturnas e crepusculares, controlada também por outros fatores ambientais. Para isso, contamos as visitas a cada minuto ao longo de 30 noites/crepúsculos em 33 árvores de cambuci em um pomar comercial, medindo as seguintes variáveis ambientais: intensidade de luz, disponibilidade de flores, temperatura, umidade e velocidade do vento. A intensidade de luz foi a única variável que explicou a visitação floral de abelhas noturnas no cambuci, a qual tem um pico em níveis intermediários de luz que ocorrem ao redor de 30 minutos antes do nascer do sol. O limiar mínimo de intensidade de luz para as abelhas começarem a voar foi de 0.00024 cd/m2, o primeiro valor registrado para abelhas noturnas e crepusculares procurando por flores em um contexto agroflorestal. Nossos resultados destacam pela primeira vez como as abelhas noturnas dependem da luz para explorar recursos e mostram que essa dependência, para abelhas em geral, não é sempre linear, como postulado por modelos teóricos prévios. Este é o primeiro passo para entender como abelhas noturnas reagem a fatores ambientais. Nossos dados também trazem alertas para possíveis efeitos negativos da poluição luminosa à noite para a interação entre cambuci e abelhas noturnas

The foraging activity of day-active bees often rely on flower availability, light intensity and temperature. However, some bees developed a nocturnal habit and fly during the dusk, dawn and night. We still do not know how these bees cope with environmental factors, especially dimmer light levels, to explore flower earlier than their diurnal relatives. Given that typical bee apposition compound eyes work better in brighter environments and function in their limits in dim-light conditions, we can expect a larger dependence of light intensity for nocturnal groups. Nocturnal and crepuscular bees are frequent visitors of cambuci (Campomanesia phaea, Myrtaceae) in southeastern Brazil. We aimed to investigate how light intensity affects flower visitation of cambuci by nocturnal and crepuscular bees, also controlling for other environmental factors. We counted visits per minute along 30 nights/twilights in 33 cambuci trees from a commercial orchard, measuring the following environmental variables: light intensity, flower availability, temperature, air relative humidity and wind speed. Light intensity is the only variable that explained flower visitation of nocturnal bees in cambuci, which peaks at intermediate light levels that occur around 30 minutes before sunrise. The minimum light intensity threshold to bees start flying is of 0.00024 cd/m2, the first recorded value for nocturnal and crepuscular bees finding flowers in an agro-forest context. Our results highlight for the first time how nocturnal bees rely on light to explore resources and show that the bees light-dependent foraging activity is not always linear, as postulated by previous theoretic models. This is the first step to understand how nocturnal bees react to environmental factors. Our findings also bring concerns about possible negative effects of light pollution at night for cambuci-crepuscular bees interaction / O forrageio de abelhas geralmente depende de disponibilidade de flores, intensidade de luz e temperatura. Contudo, algumas abelhas desenvolveram hábitos noturnos e voam durante os crepúsculos e a noite. Não se sabe como essas abelhas lidam com os fatores ambientais, especialmente os reduzidos níveis de luminosidade. Dado que os olhos compostos de aposição de abelhas funcionam melhor em maiores luminosidades, espera-se uma maior dependência da luz para os grupos noturnos. Abelhas noturnas e crepusculares são visitantes frequentes do cambuci (Campomanesia phaea, Myrtaceae) no sudeste do Brasil. Nosso objetivo foi investigar como a intensidade de luz afeta a visitação floral do cambuci por abelhas noturnas e crepusculares, controlada também por outros fatores ambientais. Para isso, contamos as visitas a cada minuto ao longo de 30 noites/crepúsculos em 33 árvores de cambuci em um pomar comercial, medindo as seguintes variáveis ambientais: intensidade de luz, disponibilidade de flores, temperatura, umidade e velocidade do vento. A intensidade de luz foi a única variável que explicou a visitação floral de abelhas noturnas no cambuci, a qual tem um pico em níveis intermediários de luz que ocorrem ao redor de 30 minutos antes do nascer do sol. O limiar mínimo de intensidade de luz para as abelhas começarem a voar foi de 0.00024 cd/m2, o primeiro valor registrado para abelhas noturnas e crepusculares procurando por flores em um contexto agroflorestal. Nossos resultados destacam pela primeira vez como as abelhas noturnas dependem da luz para explorar recursos e mostram que essa dependência, para abelhas em geral, não é sempre linear, como postulado por modelos teóricos prévios. Este é o primeiro passo para entender como abelhas noturnas reagem a fatores ambientais. Nossos dados também trazem alertas para possíveis efeitos negativos da poluição luminosa à noite para a interação entre cambuci e abelhas noturnas

Les abeilles en libre vol montrent des capacités cognitives visuelles remarquables mais les bases neurales sous-jacentes ne peuvent pas être étudiées chez des insectes en vol. À l'inverse, le cerveau des abeilles immobilisées est accessible mais ne permet pas d'explorer l'apprentissage visuel. Pour dépasser cette limite, notre objectif a été d'établir un dispositif de réalité virtuelle pour pouvoir tester l'apprentissage visuel sur des abeilles attachées. Dans un premier temps, les abeilles ont été testées sur leur capacité à discriminer des couleurs en s'appuyant sur les renforcements positifs ou négatifs qui leur étaient associés. Ces expériences ont permis de mettre en évidence le rôle de la vision active dans la réalité virtuelle et l'importance de la phototaxie dans ce type de système. Grâce à ce dispositif, un apprentissage non élémentaire en réalité virtuelle, le patterning négatif, a été mis en place. Ainsi il a été montré que les abeilles étaient capables de résoudre cette tache en réalité virtuelle malgré sa complexité. Enfin, en s'appuyant sur le protocole de discrimination de couleurs, l'activation du cerveau a été étudiée au cours d'un test de mémoire des couleurs en analysant l'expression de gènes considérés comme des marqueurs de l'activité neurale. Les résultats de cette thèse, fournissant deux protocoles de réalité virtuelle solides pour étudier les apprentissages visuels élémentaires et non élémentaires, constituent une avancée considérable vers la possibilité de comprendre les bases neurales sous-jacentes à ces apprentissages chez l'abeille qu'ils soient simples ou complexes. / Free flying bees are known for their impressive visual cognition abilities, but the neural bases underlying those are poorly studied because of the difficulty to explore the brain in a flying insect. Conversely, it is possible to have access to the brain with tethered bees but, until now, no studies explored visual learning. To bypass this limitation, our aim was to establish a virtual reality device to test visual learning in tethered bees. First, bees were tested for their abilities to learn to discriminate colors according to the reinforcement associated to each of them. These experiments allowed to highlight the role of the active vision in virtual reality and the importance of phototaxis in this kind of device. Driven by these good results, we explored the non- elementary visual learning in bees and, more specifically, the negative patterning. The results suggest that bees were able to resolve this task in virtual reality despite its complexity. Finally, using the protocol of color discrimination, the brain activation has been explored during a color memory recall thanks to a quantification of immediate early genes considered as neural markers. This thesis provides two solid virtual reality protocols to study elementary and non-elementary visual learning in honey bees. This constitutes a huge advance and will allow to go further towards the understanding of the neural bases of simple and complex visual learning.

Na presente tese estudei a biologia de Centris (Paracentris) burgdorfi, uma abelha solitária de ampla distribuição no Brasil. O único local de nidificação conhecido até o momento fica em uma área de dunas, no nordeste do Brasil, à 25 km da cidade de Natal. Neste local as fêmeas nidificam exclusivamente em paleodunas à cerca de 1 km do mar. Estudei o sistema de acasalamento da espécie, onde pude constatar que a alta competição por fêmeas próxima ao ninho faz com que o macho tenha que retirar a fêmea do local para conseguir o contato genital. Nenhuma fêmea foi vista acasalando mais de uma vez e, logo após a cópula a fêmea dá início à construção do ninho. O ninho é constituído de um túnel raso com acesso às células de cria, construídas uma ao lado da outra. Avaliei o número de viagens que a fêmea faz para a coleta de óleo e pólen e o tempo despendido em cada ação dentro do ninho (deposição de pólen, óleo, ovoposição e operculação). Durante o período de construção das células as fêmeas não dormem dentro do ninho, e sim, em ramos de Krameria tomentosa, a planta utilizada como fonte de óleo no local. Buscando ampliar nosso conhecimento sobre a espécie, procurei outras populações no Brasil para que pudesse avaliar o nicho trófico. Utilizei o pólen encontrado no corpo das fêmeas para inferir sobre a dieta parcial de adultos e imaturos. Além da área de dunas, no Nordeste, encontramos C. burgdorfi no cerrado em Cavalcante, Goiás e em áreas de campo de altitude, em Ponta Grossa, Paraná. Através da análise polínica, constatei a importância de plantas do gênero Chamaecrista como fonte de pólen, sendo este um dos poucos gêneros compartilhados entre os três locais. Krameria grandiflora foi a fonte de óleo em Cavalcante e em Natal, e Angelonia integérrima, foi a fonte de óleo no Paraná. Isso revela a amplitude de nicho trófico em C. burgdorfi não apenas em relação às espécies de plantas utilizadas na dieta mas, também, quanto ao tipo de elaióforo que a fêmea consegue acessar (epitelial e tricromático). Esta plasticidade possibilita a ampla distribuição da espécie em diferentes fitofisionomias. Analisei nutricionalmente a dieta na provisão da cria de C. burgdorfi do nordeste do Brasil e de células de cria de Centris (Paracentris) pallida, coletadas no sudoeste dos Estados Unidos. Centris pallida é uma espécie de Centridini que perdeu o comportamento da coleta de óleo. Centris burgdorfi possui uma dieta mais rica em lipídeos e proteínas, sendo a dieta de C. pallida mais rica em carboidratos. A dieta mais protéica de C. burgdorfi se deve à presença de Chamaecrista já que plantas que anteras poricidas contem mais proteínas em comparação às não-poricidas, como é o caso das fontes de pólen de C. pallida (Parkinsonia e Olneya) / In the present thesis, I studied the biology of Centris (Paracentris) burgdorfi, a solitary bee of wide distribution in Brazil. The only nesting site known is in a dune area in northeastern Brazil, 25 km from the city of Natal. In this place, the females nest exclusively in petrified dunes about 1 km from the sea. I studied the mating system of the species, where I could verify that the high competition by females near the nest forces the male to carry the female to another place to mate. No female was seen mating more than once and, soon after copulation, the female begins to construct the nest. The nest consists of a shallow tunnel with access to the brood cells. I evaluated the number of trips that the female made to the collection of oil and pollen and the time spent in each action within the nest (depositions of pollen, oil, oviposition and operculation). During the period of construction of the cells the females do not sleep inside the nest, but in branches of Krameria tomentosa, the plant used as source of oil. In order to increase our knowledge about the species, I searched for other populations in Brazil so that I could evaluate the trophic niche. I used pollen found in the body of females to infer about the partial diet of adults and immature. In addition to the dune area in the Northeast, I found C. burgdorfi in the tropical Savanna (Cerrado) in Cavalcante, state of Goiás and in high altitude field areas, in Ponta Grossa, state of Paraná. Through pollen analysis, I verified the importance of plants of the genus Chamaecrista as a source of pollen, being this one of the few genera shared among the three sites. Krameria grandiflora was the source of oil in Cavalcante and in the Natal, and Angelonia integerrima, was the source of oil in the Ponta Grossa. This reveals the trophic niche amplitude in C. burgdorfi not only in relation to the species of plants used in the diet, but also to the type of elaiophore that the female can access (epithelial and trichromatic). This plasticity makes possible the wide distribution of the species in different phytophysiognomies. Nutritionally I analyzed the diet in the provision of C. burgdorfi offspring from northeastern Brazil and from the breeding cells of Centris (Paracentris) pallida collected in the southwestern United States. Centris pallida is a species of Centridini that has lost the behavior of the oil-collection. Centris burgdorfi has a diet richer in lipids and proteins, and the diet of C. pallida is richer in carbohydrates. The most proteinic diet of C. burgdorfi is due to the presence of Chamaecrista, since plants with poricidal anthers contain more proteins compared to non-poricidal ones, such as C. pallida (Parkinsonia and Olneya) pollen sources

Bees provide vital ecosystem services for cropping systems as well as natural landscapes. Declines in both both native bee and managed honey bee (Apis mellifera L.) populations has brought attention to the significance of their role as pollinators in managed and native ecosystems. As a result, conservation efforts have been undertaken to preserve them. While considerable attention has been given to honey bees, relatively little is known about many native bee species. Of particular interest is the family Halictidae, which can comprise the majority of observed individuals in many habitats. These, often small, bees are difficult to identify, and, as a result, relatively little is known about their preferred floral hosts. Because bee species assemblages vary significantly from region to region, it is important to have an understanding of local populations and their floral hosts. It is also important to understand factors which affect the quantity and quality of floral resources, such as anthropogenic disturbance. The Pacific Northwest is a diverse landscape, with rich agricultural and wildland environments that require pollinators in order to continue to thrive. Two studies examine the interface between these two systems, the first explores how roadside disturbance, which is prevalent across the world, impacts native pollinators across habitat types, and the second explores the diet of common native species, and how that diet changes across habitat types. In these studies, it was found that roadside disturbance was associated with reduced native bee diversity and abundance in the seasonally wet Willamette Valley of Oregon, but not in the more xeric Central Oregon. Bee abundance was positively correlated with temperature. Bee diet was more diverse in areas of scarce floral resources. In both regions, exotic plants were important floral hosts, representing nearly half of observed floral visitations. This thesis presents results of species analysis, floral richness and density correlations, and comparisons of floral resources used by different bee species. Implications and recommendations for land management are discussed. / Graduation date: 2013

The objective of this study was to characterize the wild bee fauna of a managed mixed-grass prairie in southwestern Manitoba. Weekly sampling using two methods, sweep-netting and bee bowls, was conducted over two years (2005-2006) at three sites within the Yellow Quill Mixed-grass Prairie Preserve. Spatial and seasonal patterns in diversity indices, taxonomic composition and ecological composition of the bee fauna were identified and investigated in relation to sampling method, environmental conditions, and floral resource availability. A total of 7014 individual bees representing five families and 100 species were collected. Numerically, social nesters from the genera Lasioglossum and Bombus dominated, while mining species of Andrena represented the greatest species richness. Observed spatial and seasonal patterns in the abundance, diversity and composition of the bee community were strongly modified by sampling method, resource limitation in the second year and the presence of the exotic invasive plant leafy spurge (Euphorbia esula). / October 2007

No description available.

Sue Monk Kidd’s The Secret Life of Bees (2002) tells the story of a motherless fourteen-year-old Lily Owens, raised by a cruel father, who desperately searches for clues to unlock her mother’s past. Kidd’s bildungsroman reveals the incredible power of black women, particularly a group of beekeeping sisters and a black Mary, to create a safe haven where Lily can examine her fragmented life and develop psychologically, finally becoming a self-actualized young lady. Lily’s matriarchal world of influence both compares and contrasts with the patriarchal world represented in Mark Twain’s Adventures of Huckleberry Finn, exposing the matriarchy’s aptly structured ways of providing a more healing environment than is Huck Finn’s. Kidd’s novel also showcases the stylistic strategies of first person narrative point of view, language, dialect, and the motif of place in order to contextualize the social awareness and psychological development Lily gains through her journey.