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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

From wing pattern genes to the chemistry of speciation : an integrative dissection of the early stages of diversification in mimetic butterflies / Une étude intégrative des stades précoces de l’isolement reproducteur chez les papillons Heliconius

Huber, Bárbara 25 November 2015 (has links)
Comment la diversification biologique peut-elle avoir lieu malgré les échanges génétiques? Comment les barrières reproductives entre espèces évoluent-elles et fonctionnent-elles? Les changements adaptatifs de certains traits favorisent-ils la diversification et la spéciation? Ces questions ouvertes en biologie évolutive constituent la base de ce projet. Pour y répondre, nous nous sommes intéressés aux papillons du genre néo-tropical Heliconius qui constituent une partie importante des communautés diversifiées de papillons néotropicaux. Les papillons de ce groupe sont immangeables pour les prédateurs, arborent des colorations d’avertissement qui signalent leur toxicité, et miment d’autres papillons toxiques dans leurs communautés locales. Ce genre a connu une radiation adaptative des motifs colorés soumis à la sélection naturelle favorisant le mimétisme de divers signaux locaux, mais ces motifs sont également connus comme signaux intraspécifiques favorisant les appariements homogames. Mes travaux ont permis d’approfondir les connaissances actuelles sur la fonction écologique et la base génétique de la couleur des ailes chez ces papillons, et d’explorer l'importance de la couleur des ailes par rapport aux signaux chimiques au cours des premières étapes de diversification. Dans cette optique, j’ai caractérisé la divergence adaptive entre les taxons à différents stades du continuum de spéciation, par une approche intégrative combinant des données génomiques, phénotypiques, comportementales, chimiques et écologiques. Plus précisément, j’ai étudié le sous-clade de Heliconius appelé sylvaniformes, contenant des espèces de papillons aux motifs tigrés, qui participent à des relations de mimétisme avec de nombreuses autres espèces fortement apparentées ou non. Mes travaux incluent la description comparative de l'architecture génétique des motifs colorés adaptatifs parallèlement chez les espèces H. hecale et H. ismenius, en utilisant des croisements, du génotypage génomique à haut débit, et de la morphométrie des motifs colorés. J’ai également exploré l'importance de la sélection naturelle et sexuelle sur les locus contrôlant ces motifs colorés aux stades précoces de divergence dans ce genre. En particulier, j’ai analysé la structure et le maintien de la zone d’hybridation entre deux races parapatriques de H. hecale montrant des colorations différentes, en combinant la génétique et la génomique des populations, ainsi que l’analyse phénotypique de clines et des tests comportementaux sur le choix de partenaire chez les mâles. Enfin, j’ai effectué des analyses génomiques de la divergence et du flux de gènes en me basant sur des données de re-séquençage de génomes complets afin de rechercher des traces d'introgression entre des espèces co-mimétiques et étroitement apparentées. Ceci a été également couplé à des expériences de préférence et de comportement sexuel, ainsi qu’à des analyses chimiques montrant d'importantes différences dans des composés qui pourraient intervenir dans la reconnaissance spécifique et le maintien des limites entre espèces. Dans l'ensemble, mes travaux montrent que bien que la sélection agissant sur les motifs colorés des ailes ait été centrale dans la diversification du genre Heliconius, l'accumulation d'autres barrières au flux de gènes peut jouer un rôle important dans l’aboutissement du processus de spéciation. / How does biological diversification occur in the face of genetic exchange? How do reproductive barriers evolve and function? What is the role of adaptive traits in promoting diversification and speciation? These open questions in evolutionary biology are at the core of this project. In order to tackle them, we have focused on butterflies in the neo-tropical genus which are an important component of the diverse butterfly communities in the Neo-tropics. Butterflies in the genus Heliconius are unpalatable to predators, use warning colours to advertise their defences, and mimic other defended butterflies in their local communities. The genus has undergone an adaptive radiation in wing colour patterns as a result of natural selection for mimicry, and is also well known for assortative mating based on wing pattern. I have extended the current knowledge about the ecological function and the genetic basis of wing color patterns in these butterflies and explored the importance of wing coloration relative to chemical signaling in the early stages of diversification. To this aim, I have characterised the adaptive divergence between lineages at different stages of the speciation continuum, by integrating genomic, phenotypic, behavioural, chemical and ecological data. More precisely, I have studied the so-called silvaniform sub-clade of Heliconius, known for harbouring species with tiger patterns that participate in mimicry with large groups of other closely and distantly-related species. My work includes the comparative description of the genetic architecture of wing pattern adaptation in two species, H. hecale and H. ismenius, using crosses, genome-wide next-generation genotyping, and advanced morphometrics of colour patterns. I have also explored the importance of natural and sexual selection on wing-patterning loci at early stages of divergence in the genus. In particular, I have analysed the structure and maintenance of a hybrid zone between two distinctly coloured parapatric races of H. hecale by using a combination of population genetics and genomics, coupled to a phenotypic analysis of the clines and to behavioural assays on male-based mate choice. Finally, I have carried out genome-wide analyses of divergence and gene flow with whole genome sequencing data to look for evidence of introgression between coexisting, hybridising co-mimetic species. This was again coupled to experiments on mating preferences and behavior, and yielded evidence for important differences in putative pheromone signals which may mediate species recognition and the maintenance of species boundaries. Overall, my results show that although selection on wing pattern divergence have been central to the diversification of the genus Heliconius, the accumulation of other barriers to gene flow may be important for the speciation process to be completed.
112

THE LIPID COMPOSITION OF CASHMERE GOAT FIBRES

Hillbrick, Gordon Colin, kimg@deakin.edu.au January 1994 (has links)
This study examined the differences in the chemical composition, particularly fatty acids, of the lipid extracted from the fibre of bucks, does and castrated goats. The study provides a more detailed understanding of the chemical composition of buck fibre lipid and how it varies throughout the year, and also details the effect of body region and nutrition on the production and chemical composition of lipid from buck fibre. Lipid was extracted with either petroleum ether (non-polar) or chloroform/methanol azeotrope (polar) and analysed by gas chromatography and gas chromatography-mass spectrometry. The more polar solvent system extracted larger amounts of lipid and more of each individual fatty acid. The following buck specific ethyl branched fatty acids were identified: 2-ethylhexanoic, 4-ethylhexanoic, 2-ethyloctanoic, 4-ethyloctanoic, 6-ethyloctanoic, 2-ethyldecanoic, 4-ethyldecanoic, 2-ethyldodecanoic, 6-ethyldodecanoic, 4-ethyldodecanoic, 2-ethyltetradecanoic, 6-ethyltetradecanoic, 4-ethyltetradecanoic, 2-ethylhexadecanoic and 4-ethyloctadecanoic acids. Of these buck specific fatty acids only 4-ethylhexanoic (T), 4-ethyloctanoic, 4-ethyldecanoic, 4-ethyldodecanoic, 6-ethyldodecanoic (T), 4-ethyltetradecanoic, 2-ethylhexadecanoic (T) and 4-ethylhexadecanoic acids have been previously identified or tentatively identified (T) in buck fibre extracts. This shows that the chemical composition of buck fibre lipid is more complex than previously reported, and that it may be more difficult than previously thought to artificially duplicate the odour of the buck. Buck fibre samples had lower average concentrations of 2-methylpropanoic, 2-methylbutanoic, iso-pentadecanoic, anteiso-pentadecanoic, iso-hexadecanoic, anteiso-heptadecanoic, iso-octadecanoic and anteiso-nonadecanoic acids as compared with fibre samples from does, spayed does, or wethers that were castrated at one month of age. The reduced concentrations of these fatty acids in buck fibre extracts were likely to be due to the synthesis of ethyl branched derivatives of iso and anteiso fatty acids. Buck fibre samples had higher concentrations of benzoic acid as compared with fibre samples from does, spayed does, or wethers that were castrated at one month of age. The significance of these results is that non buck specific fatty acids may also make a contribution to the odour of bucks. When fibre samples were collected at various times throughout the year, it was found that the bucks had increased amounts of lipid and ethyl branched fatty acids in fibre samples shorn from March to September, as compared with fibre samples shorn in November and January. The increase in the amount of lipid and ethyl branched fatty acids corresponded with both the rutting period of the buck and the period when the buck odour was increased. This suggests that ethyl branched fatty acids could be pheromones. The variation in lipid content and fatty acid composition was also examined between fibre samples collected from different body regions of the buck during April, as alterations in sebaceous gland activity around the neck during rutting have been reported. It was found that the average amount of lipid in the neck region of the bucks was not statistically higher than the average amounts in the midside and hind regions. However, the ethyl branched fatty acid concentrations were statistically higher in the fibre from around the neck as compared with the fibre from the other body regions, which is consistent with the odour of the buck being most pronounced around the head and neck region. The lipid content and composition of fibre samples from bucks fed high and low quality diets (lucerne and pangola grass, respectively) was examined to determine the effect of nutrition on buck specific components. The high quality diet increased the amount of lipid and ethyl branched fatty acids in fibre samples collected in April from the neck, midside and hind regions, as compared with fibre samples from the corresponding body regions from bucks fed the low quality diet. Thus it may be possible for the pheromone levels of bucks to be increased by simply providing them with good nutrition. The lipid content and ethyl branched fatty acid concentrations of fibre samples increased earlier in the year for the lucerne fed bucks as compared with the pangola grass fed bucks. The lucerne fed bucks had increased concentrations of ethyl branched fatty acids in fibre samples shorn during December to June (6 months) whereas the pangola grass fed bucks had increased concentrations of ethyl branched fatty acids in fibre samples shorn during April to August (4 months). These observations show that good nutrition can result in both the earlier production of ethyl branched fatty acids and an extended period when ethyl branched fatty acids are produced. This suggests that nutrition can be used to manipulate pheromone levels in the buck. The period when the ethyl branched fatty acids were increased corresponded with the period when the plasma luteinizing hormone (LH) and testosterone concentrations, odour and sebaceous gland volume of the bucks were increased, which supports the assumption that ethyl branched fatty acids are involved in odour production and act as pheromones.
113

Human Pheromones : Psychological and Neurological Modulation of a Putative Human Pheromone

Lundström, Johan N. January 2005 (has links)
<p>The notion that humans have specialized chemicals used for communication between conspecifics, so-called pheromones, has attracted much attention and discussion. This thesis demonstrates in four separate studies that a human endogenous steroidal compound that is abundant in male sweat, androstadienone, affects women in several ways that differ to that of common odors. Specifically, androstadienone was found in Study I to have unique psychophysical characteristics in that the sensitivity distribution of the odor is bimodal with a smaller subpopulation consisting of highly sensitive individuals. Trigeminal mediation of this bimodality was experimentally excluded. Moreover, Study II demonstrated that women’s cortical activation of androstadienone exposure was found to differ to that of common odorants in that androstadienone was processed faster than two perceptually similar control odors. It was further demonstrated that a non-detectable amount of androstadienone can reliably modulate both mood and physiology in women (Study III & IV); in particular mood referring to attention processes. Study IV showed that androstadienone-induced mood changes in heterosexual women were only evident when the experiment was administered by an experimenter of different sex. The combined results from these studies suggest that androstadienone serves as a human modulator pheromone that guides our behavior by inducing subtle changes in higher cognitive processes in relation to the ecological context at hand. A new definition of human pheromones is proposed and discussed in relation to the obtained results.</p>
114

Human Pheromones : Psychological and Neurological Modulation of a Putative Human Pheromone

Lundström, Johan N. January 2005 (has links)
The notion that humans have specialized chemicals used for communication between conspecifics, so-called pheromones, has attracted much attention and discussion. This thesis demonstrates in four separate studies that a human endogenous steroidal compound that is abundant in male sweat, androstadienone, affects women in several ways that differ to that of common odors. Specifically, androstadienone was found in Study I to have unique psychophysical characteristics in that the sensitivity distribution of the odor is bimodal with a smaller subpopulation consisting of highly sensitive individuals. Trigeminal mediation of this bimodality was experimentally excluded. Moreover, Study II demonstrated that women’s cortical activation of androstadienone exposure was found to differ to that of common odorants in that androstadienone was processed faster than two perceptually similar control odors. It was further demonstrated that a non-detectable amount of androstadienone can reliably modulate both mood and physiology in women (Study III &amp; IV); in particular mood referring to attention processes. Study IV showed that androstadienone-induced mood changes in heterosexual women were only evident when the experiment was administered by an experimenter of different sex. The combined results from these studies suggest that androstadienone serves as a human modulator pheromone that guides our behavior by inducing subtle changes in higher cognitive processes in relation to the ecological context at hand. A new definition of human pheromones is proposed and discussed in relation to the obtained results.
115

Informacijos perdavimo lytiniais feromonais tyrimas Canis familiaris pavyzdžiu / Information transfer by means of sex pheromones in test object Canis familiaris

Juškevičiūtė, Justina 16 August 2007 (has links)
Dabar vis daugiau mokslininkų bando identifikuotus gyvūnų feromonus sintetinti ir panaudoti praktinėms reikmėms, pavyzdžiui, vabzdžių sintetinių feromonų analogus naudoti kovai su žemės ūkio kenkėjais. Tačiau tik XX amžiaus pabaigoje pradėta domėtis ir žinduolių feromonais. Viena iš naujų tiriamų sričių yra: lytinių feromonų įtaka gyvūnų lytinei elgsenai. Lytinė elgsena yra vienas iš svarbiausių šunų kaip ir, bet kurios kitos gyvosios sistemos egzistavimo garantas, todėl tai paskatino mus išsamiau paanalizuoti šunų lytinės elgsenos modelį (asistavimą). Taip pat mūsų tikslas buvo sumodeliuoti tokį biotestavimo modelį kaip materiali informacija paveikia individo (šuns) elgesį ir nustatyti bei apibūdinti kas tai yra ta informacija, šiuo atveju – cheminė medžiaga. Tyrimai buvo atlikti 2005 – 2007 metais. Buvo surinkti šlapimo ėminiai iš skirtingų šunų veislių devynių kalių nerujos ir rujos metu. Ėminių rinkimo metodika buvo specialiai sukurta įgyvendinti mūsų užduotis ir yra originali. Viena dalis rinkimo metu surinktos medžiagos buvo išsiusta į Karališkąjį Technologijų Institutą Stokholme (Royal Institute of Technologies). Atlikus pirminius ėminių tyrimus, nustatyta jog tik rujojančių kalių šlapime yra TC medžiaga. Antra dalis rinkimo metu surinktos medžiagos buvo naudota biotestui. Po to buvo atlikti du biotestavimai lauko sąlygomis Pietų Rusijos aviganių veislyne „Balandis“. Šiuose tyrimuose buvo atlikti testavimai su šios veislės patinais pagal 7 mūsų sukurtus testavimo... [toliau žr. visą tekstą] / More and more scientists nowadays are trying to syntetic animals‘ pheromones and use them for practical purposes. Analogues of syntetic pheromones, for instance, are used in agriculture against pests. It was only in the end of the 20th century, however, that mammals‘ pheromones, too, started arousing interest. One of the new fields of resaerch is the animals‘ sexual behaviour. Sexual behaviour is one of the guarantees of dogs‘, as well as any other living systems‘ existence. Then an idea suggested itself to us to analyze more deeply the model of this type of behaviour amoung dogs. Our aim was also to set up a model of biotesting in what way material information is reflected on an individual‘s (dog‘s) behaviour and to establish what that information is. In this case – a chemical substance. The research was carried out between 2005 and 2007. Urine samples were gathered from bitches of different dogs‘ breeds then they were on the heat and when they were not on the heat. The method of taking the samples was specially created to satisfy our requirements and is original. One part of the samples gathered was sent to the Royal Institute of Technologies in Stockholm. The research conducted on the primary samples showed that the substance TC was to be found only in the urinie of bitches (females) that were on the heat. The rest of material gathered was used for examination. Then two biotests (in outside)was conducted at the South Russian Sheep – dog kennel “Balandis“. Researched... [to full text]
116

Ecology and evolution in a host-parasitoid system : Host search, immune responses and parasitoid virulence

Fors, Lisa January 2015 (has links)
In host-parasitoid systems, there is a continuous coevolutionary arms race where each species imposes a strong selection pressure on the other. The host needs to develop defence strategies in order to escape parasitism and the parasitoid must evolve counter-defence strategies in order to overcome the host’s immune defence and successfully reproduce. This makes host-parasitoid systems excellent model systems for understanding evolutionary processes underlying host race formation and speciation. In order to gain a better understanding of the complexity of host-parasitoid interactions several aspects must be considered, such as search behaviour and host selection in the parasitoid, the development of immune responses in the host and counter-defence strategies in the parasitoid. In this thesis, I investigate interactions and coevolution in a natural host-parasitoid system, consisting of five species of Galerucella leaf beetles and three species of Asecodes parasitoids, by combining behavioural ecology with chemical ecology and immunology. In the studies performed, I found that pheromone production and responses in the beetles are connected to the phylogenetic relatedness between the Galerucella species (Paper I). I found no evidence that Asecodes exploits the adult pheromone to locate host larvae, but observed an ability in the parasitoids to distinguish a better host from a less suitable one based on larval odors (Paper II). The studies also revealed large differences in immune competence between the Galerucella species, which were linked to differences in hemocyte composition in the beetle larvae (Paper III, IV). Further, the results suggest that parasitism success in polyphagous Asecodes is strongly affected by former host species of the parasitoid (Paper IV). In conclusion, the results of this thesis suggest an on-going evolution in both parasitoid virulence and host immune responses in the Asecodes-Galerucella system. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 4: Manuscript.</p>
117

Desenvolvimento de microcantilever funcionalizado com polímero condutor para a detecção de compostos orgânicos voláteis e umidade relativa

Steffens, Clarice 31 May 2012 (has links)
Made available in DSpace on 2016-06-02T19:02:41Z (GMT). No. of bitstreams: 1 4784.pdf: 6177335 bytes, checksum: d4efe41cda16378eef382581c4b2c468 (MD5) Previous issue date: 2012-05-31 / Universidade Federal de Minas Gerais / The great interest to develop microcantilevers sensors is due to several desirable properties, in particular the ability to adjust the size and structure, thus increasing the perspectives for the construction of new sensor systems. In this work, we developed functionalized microcantilever sensors with conducting polymers to detect relative humidity, volatile organic compounds and insect pheromones. The development was based on a systematic investigation, since the polymer synthesis and the film formation until the sensing step. For this purpose, we studied two treatments to clean the microcantilevers surfaces (plasma and piranha solution). Also, appropriate ways for the sensors functionalization were evaluated, using spin-coating and thermoelastic probe techniques. The polyaniline solutions were obtained by the in-situ and interfacial synthesis. This way, the doping, morphology and the polymer structure have been investigated by the AFM, UV-Vis, FTIR, diffraction and FE-SEM techniques, and likewise the film properties. It allowed us to optimize the preparation conditions of the polyaniline films on the surface of the microcantilevers sensors to detect relative humidity and volatiles. Also, it was possible to develop sensors with polyaniline thin films, capable to detect 1 ppmv of relative humidity, and this shows that they can be used to measure large limits of detection. Moreover, the functionalized microcantilevers sensors showed a fast response time, repeatability over several cycles and exhibited lifetime longer than 6 months. The coated microcantilevers sensors showed an excellent response to the volatile organic compounds (VOCs), indicating that the sensitive layer was xiv appropriate for detection of these volatiles. The sensitivity of these sensors at VOCs increased with the polarity, thus the methanol compound showed the greatest sensitivity. It was possible to detect and evaluate different concentrations of the pheromone 2-heptanone, at different temperatures. The microcantilever sensors response not only showed an excellent sensitivity, but also a fast response time. It was observed an excellent response to deflection of the microcantilever sensors when exposed to volatile during the banana ripeness. / O grande interesse em desenvolver sensores de microcantilevers é devido às várias propriedades desejáveis, em particular a capacidade de adaptar o tamanho e a estrutura, aumentando, dessa forma, as perspectivas para a construção de novos sistemas de sensoriamento. Neste trabalho foram desenvolvidos nanossensores de microcantilever funcionalizados com polianilina, no estado de oxidação esmeraldina, para detecção de umidade relativa, de compostos orgânicos voláteis e, potenciais aplicações para detecção de feromônios de insetos e no amadurecimento de frutas. Para isso, o desenvolvimento se baseou em uma investigação sistemática, desde a síntese do polímero e a formação de filmes até a etapa de sensoriamento. Para tal, foram estudados dois tratamentos de limpeza das superfícies dos microcantilevers, o plasma e a solução piranha . Também foram avaliadas maneiras adequadas para a funcionalização dos sensores, empregando as técnicas de spin-coating, in-situ e sonda termoelástica à partir de soluções de polianilina obtidas pelas sínteses interfacial e in-situ, para a deposição de um filme fino em somente um lado da superfície do microcantilever. Dessa forma, a dopagem, cristalinidade e estrutura do polímero foram investigadas por meio das técnicas de UV-Vis, FTIR, difratometria e FE-MEV e, por conseguinte, as propriedades dos filmes. Estes estudos permitiram aperfeiçoar as condições de preparação dos filmes de polianilina sobre a superfície dos sensores de microcantilevers, para detecção de umidade relativa (%) e compostos orgânicos voláteis (COVs). Foi possível desenvolver sensores com filmes finos de polianilina, capazes de detectar umidade relativa até 1 ppmv, indicando, portanto, que os sensores xii desenvolvidos podem ser usados para medir grandes limites de detecção. Além disso, os sensores de microcantilevers funcionalizados apresentaram um tempo de resposta rápido, foram repetitivos a vários ciclos e apresentaram uma durabilidade maior que 6 meses. Os sensores de microcantilevers funcionalizados apresentaram uma excelente reposta aos COVs, indicando que a camada sensitiva foi adequada para detecção desses voláteis. A sensitividade dos sensores de microcantilever funcionalizados aos COVs aumentou com o aumento da polaridade do volátil, assim o composto que apresentou maior sensitividade foi o metanol. Foi possível avaliar e detectar diferentes concentrações do feromônio 2- heptanona em diferentes temperaturas. Os sensores mostraram uma excelente sensitividade e um tempo de resposta rápido. Foi observada uma excelente resposta de deflexão dos sensores de microcantilever quando expostos aos voláteis, durante o amadurecimento da banana.
118

A comunicação do processo reprodutivo em abelhas sem ferrão (Hymenoptera: Apidae, Meliponini) / The mating communication of stingless bees (Hymenoptera: Apidae, Meliponini)

Lucas Garcia Von Zuben 12 April 2017 (has links)
O processo reprodutivo é de extrema importância para os organismos vivos, é através dele que os indivíduos transmitem as informações contidas em seus genes para as próximas gerações. Para que qualquer indivíduo seja bem-sucedido nesse processo, o primeiro desafio a ser superado é encontrar um parceiro sexual. Para cumprir essa tarefa, machos e fêmeas comunicam sua presença utilizando uma variedade de canais sensoriais. Nas abelhas sociais,o encontro entre machos e fêmeas é um processo complexo e resultado de um refinado sistema de comunicação, mediado principalmente por sinais químicos. Embora Meliponini seja o maior e mais diverso grupo de abelhas sociais, existem poucas informações sobre a comunicação sexual desses insetos. Um fenômeno comum nesse grupo de abelhas é a formação de grandes agregados de machos nas proximidades de colônias que possuem uma rainha virgem. No entanto, os sinais envolvidos na atração dos machos e na formação desses agregados são pouco conhecidos. Desse modo, este trabalho objetivou investigar os fatores envolvidos na comunicação sexual de Meliponini. Para explorar esse problema, nós realizamos uma revisão sobre a biologia reprodutiva dessas abelhas (cap. 1), testamos o papel das forrageiras na atração de machos (cap.2), identificamos os compostos presentes nas marcas depositadas por machos nas agregações (cap.3) e investigamos os fatores relacionados à escolha dos machos por uma determinada colônia (cap. 4). Os resultados obtidos apontam que as forrageiras têm um papel central na atração dos machos e que os machos depositam ativamente seus hidrocarbonetos cuticulares nos locais de agregação. Além disso, foi possível identificar que a atratividade de uma colônia está relacionada com a sua biomassa. Assim, esses resultados contribuem para ampliar nosso conhecimento sobre o processo reprodutivo em abelhas sem ferrão e mostram que a comunicação sexual desse grupo de insetos é um processo tão complexo quanto fascinante que envolve machos, rainhas e operárias / Reproduction is the utmost important process for living organisms since it is through this process that individuals can transmit their genetic information to the next generation. To be successful in this process, the first challenge individuals need to overcome is finding a sexual partner. To accomplish this task, males and females communicate their presence using several sensorial modalities. In highly eusocial bees, this complex process is the outcome of a precise chemical communication system. Stingless bees (Meliponini) represents the most species-rich group of eusocial bees and although a lot of information related to the group can be found in the literature, very little is known about their mating communication. A common phenomenon in this group of social bees is the formation of large male aggregations in front of nests during reproductive events. However, the factors involved in the formation of such male aggregation are poorly understood. Therefore, the aim of this study was to investigate the mating communication of stingless bees. To explore this problem, we reviewed the mating biology of the bees (chapter 1), tested the role of foragers in the attraction of males (chapter 2), identified the compounds that drones deposit at the aggregation site (chapter 3) and investigated the factors related to the differential attraction of males to colonies (chapter 4). Our results suggest that foragers have a central role in the long-range attraction of males and that males actively deposit their cuticular hydrocarbons at the aggregation site. Furthermore, we observed that the number of attracted males increased with the weight of colonies, showing that the attractiveness of colonies is related to their biomass. Thus, these results contribute to improve our knowledge about the reproductive process of stingless bees and show that the sexual communication of these bees is as complex as fascinating and involves males, queens and workers
119

Obtenção de micro/nanofibras poliméricas por fiação por sopro : parâmetros e aplicação no controle de pragas agrícolas

Rempel, Silvana Pereira 20 July 2018 (has links)
Este trabalho apresenta a obtenção de micro/nanofibras de EVA utilizando o método de fiação por sopro em solução e sua possibilidade de aplicação na agricultura, no controle de pragas, através da incorporação de feromônios sexuais sintéticos. Soluções com concentração de 0,5−15% em massa de EVA em xileno: clorofórmio (96:4% em peso) foram preparadas com base no parâmetro de solubilidade do copolímero. A viscosidade das soluções, assim como o regime de concentração foi determinado por meio de medidas reológicas. A morfologia e estrutura das fibras foram avaliadas por meio de microscopia eletrônica de varredura (MEV-FEG) e difração de raios X (DRX). O perfil de liberação dos feromônios foi determinado com base na perda de massa utilizando termogravimetria (TGA). A obtenção de fibras foi possível nas soluções com regime de concentração semidiluída. As fibras apresentaram diâmetros médios de 95 a 426 nm e seus tamanhos são dependentes da taxa de alimentação. Não há evidências de que as taxas de alimentação utilizadas e a concentração tenham efeito na orientação macromolecular do EVA, assim como a utilização dos feromônios na fiação. A quantidade incorporada nas fibras, bem como a taxa de liberação dos feromônios possui influência do parâmetro de solubilidade. Portanto, dependendo da demanda de liberação é possível obter um sistema de liberação com um balanço entre taxa de liberação e tempo máximo de liberação com base na natureza do sistema polímero/solvente/feromônio. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES / This work presents the production of EVA micro/nanofibers using the solution blow spinning method and its possibility of application in agriculture, in pest control, through the incorporation of synthetic sex pheromones. Solutions with a concentration of 0.5-15% by mass of EVA in xylene: chloroform (96:4% by weight) were prepared based on the solubility parameter of the copolymer. The viscosity of the solutions as well as the concentration regime was determined by means of rheological measurements. The morphology and structure of the fibers were evaluated by means of scanning electron microscopy (SEM-FEG) and X-ray diffraction (XRD). The release profile of the pheromones was determined based on the loss of mass using thermogravimetry (TGA). Fibers were obtained in the solutions in the semi-diluted concentration regime. The fibers have diameters of 95 to 426 nm and their sizes are dependent on the feed rate. There is no evidence that feed rates used and concentration have an effect on macromolecular orientation of EVA, as well as the use of pheromones in spinning. The amount incorporated in the fibers, as well as the rate of release of the pheromones influences the solubility parameter. Therefore, depending on the release demand it is possible to obtain a release system with a balance between release rate and maximum release time based on the nature of the polymer/solvent/pheromone system.
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Estudo químico e morfológico da broca-da-coroa-foliar eupalamides cyparissias (Fabricius, 1776) (Lepidoptera: castniidae) de arecáceas / Chemical and morphological study of the palm boree, eupalamides cyparissias (Fabricius, 1776) (Lepidoptera: castniidae) from arecáceas

Costa, Dannielle de Lima 31 August 2015 (has links)
The Castniidae family is a group of Pantropical insects with about 150 species widely distributed mainly in the Malay Peninsula, Australia, South America and Central America. The caterpillars of species in this family are borer of cultures of the families Arecaceae, Bromeliaceae, Musaceae, Heliconiaceae, Orchidaceae and Poaceae. Among the species of pests Castniidae family is the borer crown leaf Eupalamides cyparissias Fab. (Lepidoptera: Castniidae), a major pest of palm trees in the Amazon region of Brazil, Ecuador, Colombia, Peru, Venezuela and Northern Panama. The damages are associated with Cocos nucifera L. (Arecales: Arecaceae) (coconut plants) and Elaeis guineensis Jacq. (Arecales: Arecaceae) (oil palm), major crops of economic importance to the state of Pará. This study aimed to observe the E. cyparissias behavior, identify glandular cells in the female ovipositors, distinguish the types of sensilla in the antennae of males and females and investigate the presence of sex pheromones in both sexes. Behavioral observations were carried out in laboratory and palm oil crops in the municipality of Moju, Pará. Histological sections of ovipositors were analyzed in light microscope (Olympus BX41). The antennas were analyzed by Scanning Electron Microscopy (SEM) using a Shimadzu, Model SSX-550 Superscan. For preparation of extracts of front and rear wings of male and female, ovipositor and male sexual organ, adults with 24 and 48 hours of age were used. For each pair of wings 300 uL of hexane (distilled HPLC grade) was used and each male sexual organ or female ovipositor 100 uL was used the same solvent, for 20 minutes, then the supernatant was transferred to a 2 ml vial. Evaluation of the bioactivity of the extracts was performed on GC-EAD and the separation and identification of compounds by GC and GC-MS. Field observations confirm that enabled moths in palm plantations in Pará are quite active in crepuscular time between 6:00 and 7:30 am and between 18:30 and 19:30 pm. Characteristic behaviors courtship as exposure of the ovipositor, clásperes exposure, ovipositor exposure and beating of wings, walk flapping, abdominal movements, guided walk to the opposite sex, antennation and contact have been observed. Histological analysis identified glandular cells located near the cuticle on the dorsal proximal region of the ovipositor. In the antennae of male and female five types of sensilla were observed: trichodea, chaetica, squamiformia, coeloconica, and auricillica. Characteristic behaviors observed and morphological structures allow us to infer chemicals mediating the communication between these insects. The specific compounds males were identified 7,11-hexadecadienal, 7,11-hexadecadien-1-ol, espringene, geranyl linalool and geranyl geraniol. Female specific compounds were identified α-coapaene, trans-caryophyllene, 1-hexadecanol, 9-Hexadecenoic acid, octadecyl ester and Hexadecanoic acid, octadecyl ester. GC-EAD analysis revealed female antenna activity for geranyl geraniol compounds, nonacosane and β-sitosterol present in the extracts of the rear wing of males. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A família Castniidae é um grupo de insetos com cerca de 150 espécies, e distribui-se na Península Malaia, Austrália, América do Sul e América Central. As lagartas de espécies desta família são brocas de culturas das famílias Arecaceae, Bromeliaceae, Musaceae, Heliconiaceae, Orchidaceae e Poaceae. Dentre as espécies-pragas da família Castniidae está a broca-da-coroa-foliar, Eupalamides cyparissias (Fabricius, 1776) (Lepidoptera: Castniidae), uma importante praga de palmeiras da região Amazônica do Brasil, Equador, Colômbia, Peru, Venezuela e norte do Panamá. Os prejuízos mais evidentes estão associados às plantas de Cocos nucifera L. (Arecales: Arecaceae) (coqueiro) e Elaeis guineensis Jacq. (Arecales: Arecaceae) (dendezeiro), principais culturas de importância econômica para o estado do Pará. Este trabalho teve por objetivo observar o comportamento de E. cyparissias, identificar células glandulares nos ovipositores de fêmeas, distinguir os tipos de sensilas nas antenas de machos e fêmeas e investigar a presença de feromônios sexuais em ambos os sexos. As observações comportamentais foram realizadas em laboratório e em culturas de dendê no município de Moju, Pará. Os cortes histológicos dos ovipositores foram analisados em microscópio de luz (Olympus, BX41). As antenas foram analisadas por microscopia eletrônica de varredura (MEV) utilizando-se microscópio Shimadzu, modelo SSX-550 Superscan. Para preparação dos extratos das asas anterior e posterior de machos e fêmeas, do ovipositor e do órgão sexual dos machos foram utilizados adultos com 24 e 48 horas de idade. Para cada par de asas foi utilizado 300 μL de hexano (grau HPLC destilado) e para cada órgão sexual do macho ou ovipositor da fêmea utilizou-se 100 μL do mesmo solvente, permanecendo por 20 minutos, em seguida o sobrenadante foi transferido para um vidro de 2 mL. A avaliação da bioatividade dos extratos foi realizada por cromatografia gasosa acoplada ao detector eletroantenográfico (CG-EAD) e a separação e identificação dos compostos através do cromatógrafo gasoso (CG) e cromatografia gasosa acoplado à espectrometria de massas (CG-EM). Observações de campo permitiram confirmar que mariposas em plantios de dendê no Pará são bastante ativas em horário crepuscular entre as 6:00 h e 7:30 h e entre as 18:30 h e 19:30 h. Comportamentos característicos de corte como exposição do ovipositor, exposição de clásperes, exposição do ovipositor e bater das asas, caminhar batendo as asas, movimentos abdominais, caminhada orientada ao sexo oposto, antenação e contato foram observados. A análise histológica permitiu identificar células glandulares localizadas próximas a cutícula na região proximal dorsal do ovipositor. Nas antenas de machos e fêmeas cinco tipos de sensilas foram observadas: tricóide, caética, esquamiforme, coelocônica e auricílica. Comportamentos característicos observados e as estruturas morfológicas permitem inferir substâncias químicas mediando a comunicação entre esses insetos. Os compostos específicos de machos identificados foram, 7,11-hexadecadienal, 7,11-hexadecadien-1-ol, espringeno, geranil linalol e geranil geraniol. Como compostos específicos de fêmeas foram identificados α-coapaeno, trans-cariofileno, 1-hexadecanol, 9-hexadecenoato de octadecila e hexadecanoato de octadecila. Análise de CG-EAD revelou atividade antenográfica da antena da fêmea frente aos compostos geranil geraniol, nonacosano e β-sitosterol presentes nos extratos da asa posterior dos machos.

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