Rozprawy doktorskie na temat „Tipulae”

Caenorhabditis elegans est un organisme modèle couramment utilisé pour étudier les processus de développement tels que la formation de la vulve. Ce processus repose sur l'induction précise des cellules qui donnent naissance à la vulve. Les destins cellulaires résultants sont organisés en un motif caractéristique, qui est conservé tout au long du Caenorhabditis et des nématodes rhabditides. En contraste avec cette conservation des cellules vulvaires, ma thèse présente deux axes d'étude qui ont révélé des signatures d'évolution des voies de développement contrôlant l'induction vulvaire. Dans le premier, je présente un changement des motifs cis-régulateurs nécessaires à l'expression cellulaire spécifique de lin-3 (EGF), un gène codant pour la molécule de signalisation qui induit le destin des cellules de la vulve. Les trois sites de liaison aux facteurs de transcription requis pour l'expression de lin-3 chez C. elegans ne sont observés que chez les espèces du groupe Elegans. En utilisant des techniques de FISH à molécule unique et d'édition de génome, je montre que le remplacement des sites endogènes de C. elegans par un fragment de 58 pb contenant un seul site (provenant de C. angaria) produit des niveaux d'ARNm de type sauvage de type lin-3. Je conclus que l'évolution compensatoire pour l'exigence de sites de liaison de C. elegans s'est produite en cis. Dans la deuxième partie de mon étude, j'ai utilisé une approche de cartographie par séquençage et une collection de mutants de la vulve chez Oscheius tipulae, voisin de C. elegans dans le clade rhabditid, afin d'identifier les mutations dans les gènes agissant sur la spécification du modèle de destin des cellules de la vulve. La seule mutation collectée pour rendre les animaux sans vulve correspond à une délétion de la région cis-régulatrice contrôlant l'expression de O. tipulae lin-3, ce que j'ai confirmé par l'édition du génome de CRISPR / Cas9. Les mutants présentant un excès d'induction de la vulve portent des lésions moléculaires dans la voie plexin / semaphorin, un système de signalisation cellulaire qui, selon moi, agit dans le positionnement antéropostérieur des cellules donnant lieu à la vulve par analyse microscopique. Enfin, d’autres animaux d’O. tipulae dont le destin de cellules vulvaires est perturbé présentent des mutations dans des composants de la voie Wnt; pour cette raison, j'ai étudié les profils d'expression des ligands Wnt d'O. tipulae et révélé leur conservation avec C. elegans. Ces deux études mettent en évidence le processus de dérèglement du système de développement (DSD) en tant que processus évolutif qui se produit lors de la formation de la vulve sur des nématodes rhabditides
Caenorhabditis elegans is a model organism commonly used to study developmental processes such as vulva formation. This process relies on the precise fate induction of the cells that give rise to the vulva. The resultant cellular fates are arranged into a characteristic pattern, which is conserved across the vulva development of Caenorhabditis and rhabditid nematodes. In contrast to this extensive conservation of the vulval cell fate pattern, my thesis presents two lines of study that revealed signatures of evolution in developmental pathways controlling vulval induction. In the first one, I present a turnover of cis-regulatory motifs required for the cell-specific expression of lin- 3 (EGF), a gene coding for the signalling molecule which induces vulva cell fates. The three transcription factor binding sites required for lin-3 expression in C. elegans are observed only in species of the Elegans group. Using single-molecule FISH and genome editing techniques, I show that the replacement of the endogenous C. elegans binding sites by a 58 bp fragment containing a single site (coming from C. angaria), produces wild-type mRNA levels of lin-3. I conclude that compensatory evolution for the requirement of C. elegans binding sites occurred in cis. In the second line of study, I used a mapping-bysequencing approach and a collection of vulva mutants in Oscheius tipulae, a neighbour of C. elegans in the rhabditid clade, to identify mutations in genes acting on vulva cell fate pattern specification. The only collected mutation to render animals vulvaless corresponds to a deletion of the cis-regulatory region controlling the expression of O. tipulae lin-3, which I confirmed by CRISPR/Cas9 genome editing. Mutants with an excess of vulva induction carry molecular lesions in the plexin/semaphorin pathway, a cell signalling system which I show to act in the antero-posterior positioning of the cells giving rise to the vulva by microscopic analysis. Finally, other O. tipulae animals with disrupted vulval cell fate pattern hold mutations in components of the Wnt pathway; for this reason, I investigated the expression profiles of Wnt ligands of O. tipulae and revealed their conservation with C. elegans. Both of these studies highlight the process of Developmental System Drift (DSD) as an evolutionary process occurring on vulva formation of rhabditid nematodes

A região N-terminal de OTI-VIT-1 foi expressa e os polipeptídeos recombinantes foram purificados. OTI-VIT-1 pode ser homólogo da vitelina YP170B de C. elegans. Foram identificados um intron na região 5´ e dois na região 3´ do gene Oti-vit-1. Antissoro monoespecífico para PVIT1HisC confirmou que o gene Oti-vit-1 codifica VT1. O polipeptídeo recombinante P40-H, correspondente à região N-terminal da proteína OTI-VIT-6 interage com um polipeptídeo de aproximadamente 100 kDa (P100) presente em extratos proteicos totais de O. tipulae. Estudamos também o papel da Proteína Microssômica Transportadora de Triglicerídeos (MTP) na biossíntese de Vitelogenina do nematoide C. elegans. Ensaios de RNAi em C. elegans, utilizando parte da sequência do gene da MTP (Cel-dsc-4) foram realizados nas linhagens N2 e DH1033. Microscopia de fluorescência de vermes adultos da linhagem DH1033, submetidos a RNAi, mostrou acúmulo de YP170B::GFP no interior dos enterócitos. Este acúmulo sugere a participação da MTP na secreção de VTG. Análise imunológica da vitelogenina nestes mesmos vermes não detectaram alterações no processamento de CEL-VIT-6, sugerindo que o mesmo ocorra não só no pseudoceloma, mas também no interior dos enterócitos.
The N-terminal region of OTI-VIT-1 was expressed and the recombinant polypeptides were purified. OTI-VIT-1 may be homologous to the vitellin YP170B from C. elegans. We identified an intron in the 5 \'region and two in 3\' region from Oti-vit-1. Monospecific antisera to PVIT1HisC confirmed that the gene Oti-vit-1 encodes VT1. The recombinant polypeptide P40-H, corresponding to the N-terminal region of the protein OTI-VIT-6, interacts with a polypeptide of approximately 100 kDa (P100) present in total protein extracts of O. tipulae. The role of microsomal triglyceride transfer protein (MTP) in the biosynthesis of vitellogenin was studied in the nematode C. elegans. Trials of RNAi in C. elegans, using the sequence of the MTP gene (Cel-dsc-4) were performed in the strains N2 and DH1033. Fluorescence microscopy of adult worms of strain DH1033, subjected to RNAi, showed accumulation of YP170B:: GFP within the enterocytes. This accumulation suggests the involvement of MTP in the secretion of VTG. Analysis using anti-vitellogenin immune serum did not detect changes in the processing of CEL-VIT-6, suggesting that it occurs not only in pseudocoelom but also within the enterocytes.

Bryophytes are rarely used as a food source by any animal species, but the genus Tipula (Diptera, Tipulidae) contains some of the few insect species able to feed, and complete their life-cycle, on bryophytes. Vegetation particle volumes ingested by larvae of eleven Tipula species increased only marginally between instars and not to the extent expected from the rate of growth of body mass. Early and late instars within a species frequently ingested similar sized particles. The overall efficiency of digestion of vegetation particles was low and similar between the four instars of each of the eleven species. Generally, the only method by which later larval instars can obtain a higher proportion of nutrients is by feeding on a larger number of smaller vegetation particles and not by ingesting large particles. In feeding choice experiments, Tipula confusa preferred moss species from woodland habitats, whereas Tipula subnodicornis did not show an overall preference for either woodland or moorland moss species. Tipula subnodicornis also showed a less extensive hierachical preference/avoidance than Tipula confusa for the ten moss species investigated. The moss species Campylopus paradoxus and Sphagnum papillosum accumulated Pb(^2+) ions and Zn(^2+) ions to high concentrations. There was some evidence that Tipula subnodicornis larvae were deterred from feeding on these mosses with high levels of introduced heavy metal ions. Tipula montana was able to thrive and complete its life-cycle in Britain at lower altitudes than had been previously thought. Individuals of this species show a combination of one-year and two-year life-cycles at Waskerley Common. The feeding methods employed by Tipula species can explain why some of them have remained as consumers of bryophytes.

Studies were carried out to investigate the development of Tipula oleracea as a pest of winter cereals in north-east Scotland. Oilseed rape was identified as an important contributing factor to the appearance of this species in winter cereals. Laboratory experiments showed that T. oleracea preferred to egg-lay into oilseed rape crops rather than winter cereals. Field surveys established that larvae were present during the winter within the oilseed rape. Further experimentation showed that larvae reared on diets of oilseed rape, out-performed those fed on winter cereals, in terms of growth, successful development, and subsequent fecundity of emerging females. Studies on behaviour showed that adults emerging from within the oilseed rape in June were trapped by the oilseed rape canopy and that 'normal' dispersal was restricted. Flies could, however, move between plant stalks underneath the canopy, suggesting that mating and egg-laying could continue. It was confirmed that T.oleracea, usually had two flight periods in north-east Scotland, in June, and again in August-September. Population studies determined that adult emergence was variable, suggesting a useful survival strategy, should peak emergence coincide with poor conditions for larval survival. Studies on growth established that the life-cycle of T. oleracea was responsive to temperature and field studies showed that two generations could be completed during the summer months within the oilseed rape crop. It was also shown that T. oleracea had a high egg-laying capacity and had no requirement for a larval diapause. The population dynamics of this species are suited to the exploitation of short term habitats, such as those created within one year arable rotations.

La tipule européenne (Tipula paludosa Meigen) est un insecte ravageur de nombreuses espèces de plantes fourragères et ornementales qui a récemment fait son apparition sur les terrains de golf de la région de Québec. Ce projet de recherche visait à développer les connaissances sur la tipule européenne au Québec afin d’élaborer des stratégies de gestion des populations sur les terrains de golf de façon à réduire l’utilisation d’insecticides. Le dépistage a été effectué sur quatre terrains de golf afin de caractériser le complexe d’espèces de Tipuloidea, le cycle saisonnier de la tipule européenne et la distribution spatiale des larves sur un terrain de golf. Une grande diversité d’espèces de Tipuloidea a été observée sur les terrains de golf malgré la nette dominance de la tipule européenne. La tipule européenne a complété une génération par année sur les terrains de golf visités dans la région de Québec. Enfin, les larves étaient plus abondantes dans les zones d’herbes longues ainsi que dans les pourtours du vert et départs.

This study investigated the ecology of a boreo-alpine crane-fly, Tipula montana Curtis (Diptera: Tipulidae), on a Scottish mountain summit. It explored adaptation to the upland environment, placing emphasis on sources of variation in growth, abundance, and low temperature tolerance. The development stages of larvae were reliably identified from measurements of the spiracular disc diameter. The sex of larvae were distinguished by the bimodal frequency distribution of weights in the 4^th instar. Larvae were sampled by hand searching and collecting off snow patches, between 1994 and 1996. The timing and size of development stages indicated that the population possessed a 2-year life cycle, supported by evidence from adult emergence. However, by rearing larvae of known developmental stage at the field site, it was shown experimentally that microhabitat could affect growth, and that it was likely to be related to temperature. In the laboratory, pre-pupal development was shown to be temperature dependent. 2^nd instar larvae were reared on single bryophyte diets, from a range of genera. They were all capable of growth and moulting, although final weights differed by a factor of 2. A pair-wise preference experiment, using 4^th instars, showed the individuals broadly chose bryophyte foods as expected from their quality, although the sedge Carex bigelowii was preferred over all mosses. No intersexual difference was detected. The observational method of assessing preference, compared to faecal pellet analysis, showed a bias towards some species, perhaps because they acted as a refuge. The pellet contents of a small number of larvae from the field were largely unidentifiable. Larval cold tolerance was investigated in the laboratory. The supercooling points of 3 different species (T. montana, T. varipennis & T. confusa), from upland and montane habitats, were very similar in autumn and spring, ranging from means of -4.5 to -6.0^oC.

Wireworms and leatherjackets, the larvae of click beetles (Agriotes spp) and crane flies (Tipula spp) respectively, are subterranean pests of grass, cereals and vegetables and are present throughout the UK and Europe. Soil cores, pheromone traps and water traps were used to measure populations. The populations of larvae were compared to those of adults. Leatherjackets and crane flies were found to be correlated, as were A. obscurus click beetle and wireworm populations. Annual variation in trap catches was observed. Populations were related at a number of spatial scales to cultural, physical and chemical variables. Spatial structure of populations was identified at all scales (sub field, field and landscape) using SADIE analysis, Moran's I and Taylor's Power Law, but the presence or absence of discernable spatial structure was dependant on species, population and annual variation. Environmental variables were linked to populations using multiple regression; the most common variable for all species were the number of years in grass, but the populations of each species and life stage were defined by its own set of variables. Important population defining variables were assessed as potential organically compliant cultural pest control methods. These included rolling, cultivation and crop rotation, but none could be definitively recommended as control methods without further work. In addition, pheromone traps for click beetles were characterised, it was found that the three species of click beetles had differential speeds of travel and the traps had differing effective ranges. A. lineatus were found to travel the fastest, A. obscurus slower and A. sputator travelled slowest. The maximum sampling range (over 30 days) was greatest for A. lineatus, less for A. obscurus and least for A. sputator.

The aim of this thesis is to undertake a theoretical analysis of the dynamics of change in pre-Ngāi Tahu and Ngāti Māmoe oral traditions of Te Waipounamu to gain a deeper understanding of their nature, function, evolution and meaning. For the purposes of this thesis a framework will be established to classify changes to encompass different types of alterations made pre-contact and post-contact to authentic and un-authentic oral traditions. This model will analyse the continuum of change and will be applied in later chapters to pre-Ngāi Tahu and Ngāti Māmoe traditions to gain an understanding of the dynamics, evolution and construction of the oral traditions of Te Waipounamu. This study of the morphology of tradition will demonstrate they were never fixed but evolved alongside their communities as they adapted to ensure tribal identity and mana was firmly entrenched in their local landscape. A major component of this thesis will be analysis of Waitaha traditions centring upon three key questions; firstly who were Waitaha peoples, secondly, where were they from, and thirdly, were they, and do they continue to be separate social units? This thesis will contribute to this discussion by analysing literature concerning pre-Ngāi Tahu and Ngāti Māmoe tribal identities to ascertain not just who they were and where they were from but how their identities have been constructed and modified over time. Analysis will examine the role of oral tradition in establishing tribal identity and how Waitaha traditions were changed both pre and post-contact to suit the cultural, political and ideological imperatives of the time, providing an insight into how our ancestors perceived, recollected and constructed the past to suit the needs of the present.

Les préoccupations actuelles concernant l'exploitation sécuritaire des centrales nucléaires existantes et la conception d’architectures spéciales envisagées pour la quatrième génération de réacteurs nucléaires se combinent avec l’intérêt plus prononcé pour l'efficacité et la fiabilité de l'équipement d'un système énergétique. Cela fait que dans un souci de meilleure compréhension et optimisation basée sur des moyens modernes de conception assistée par l’ordinateur, l'étude de différentes parties de ces systèmes fait de plus en plus l’objet de recherches approfondies. . Parmi les types proposés pour la quatrième génération de réacteurs nucléaires font partie ceux ayant comme agent de refroidissement les sels fondus, respectivement le sodium fondu. En raison de leurs propriétés physiques, les sels fondus et le sodium liquide ont le potentiel d'être déplacés par les pompes électromagnétiques. Cet ouvrage est à la fois une étude approfondie des phénomènes qui se produisent en raison de l'écoulement du fluide dans le champ électromagnétique d’une pompe électromagnétique - interaction magnétohydrodynamique - et un rapport sur les capacités et les avantages des outils informatiques modernes pour faciliter la conception et l'optimisation des pompes électromagnétiques. Afin d’atteindre l'objectif principal de la thèse, notamment une meilleure compréhension des phénomènes interdépendants spécifique à l’opération des pompes électromagnétiques, deux objectifs secondaires ont été considérés. Le premier objectif concerne la pleine exploitation des modèles électromagnétiques numériques en éléments finis afin d'obtenir autant d'informations que possible sur le comportement des pompes électromagnétiques, dans l’hypothèse où on ne tient pas compte de l'écoulement des fluides. Le deuxième objectif était la construction des modèles numériques qui réunissent l’électromagnétisme et la dynamique des fluides, respectivement des modèles numériques qui regroupent les deux phénomènes caractérisant l’écoulement magnétohydrodynamique dans les canaux des pompes électromagnétiques. Dans l'étude dédiée au pompage électromagnétique de sels fondus, la thèse met en évidence des problèmes spécifiques liés à la génération de forces électromagnétiques dans les fluides faibles conducteurs d'électricité et fournit des résultats sur les applications où le pompage électromagnétique de sels fondus peut être efficace. À l’aide des modèles électromagnétiques nous avons obtenu des informations importantes sur l'influence du nombre de pôles électromagnétiques et de la fréquence d’alimentation sur la caractéristique Pression - Vitesse des pompes annulaires à induction. Ils ont été analysés le phénomène de blindage créé par les parois métalliques - avec des répercussions négatives sur les performances de la pompe, les effets de freinage exercés à l'entrée et à la sortie du canal de la pompe et la relation entre la capacité de surcharge hydrodynamique et la caractéristique Pression - Vitesse des pompes à induction. Une section spéciale a été consacrée à l'analyse de la dépendance de la force électromagnétique du temps et de l’espace et à l’étude de non-uniformitées des quantités de nature électromagnétique en direction azimutale dans les pompes annulaires à induction.Dans le chapitre qui traite de l'interaction magnétohydrodynamique à base de modèles couplés, ils sont proposés deux modèles qui couplent l'électromagnétisme et l’écoulement. Ils sont présentés les avantages des modèles couplés, en matière de la précision des résultats, par rapport aux modèles électromagnétiques. Il est également présenté l'évolution des profils de vitesse, de densité de force et de courant sous l'influence du champ électromagnétique et de l’écoulement de sodium à vitesses différentes. Les contributions de la thèse sont complétées par des observations importantes sur les méthodes de travail et les logiciels utilisés tout au long de l'étude
The actual concerns with respect to safe operation of existing nuclear plants and to designing special architectures envisaged for the fourth generation of nuclear reactors, corroborated with the increasing interest for efficiency and reliability of any equipment belonging to an energetic system, make that more and more research endeavors to be devoted to the study of various parts of these systems for a better understanding and optimization based on modern techniques of computer aided design. Among the types proposed for the fourth generation of nuclear reactors belong those that have as cooling agent molten salts, respectively liquid sodium. Many reactors of previous generations use mechanical pumps of special design for driving the coolants. Molten salts and liquid sodium, thanks to their physical properties, have the potential to be driven using electromagnetic pumps. Although the technology of electromagnetic pumping of electroconductive fluids was developed since the first half of the last century, currently it undergoes a revival due to the reconsideration of its multiple technological and security advantages. This work is both an intimate study of the phenomena that occur as a result of the electroconductive fluids flow in the electromagnetic field of an electromagnetic pump – magnetohydrodynamic interaction - and a report on the capabilities and advantages of modern computational tools to facilitate design and optimization of electromagnetic pumps.To achieve the principal goal of deeper understanding of the interdependent phenomena specific to electromagnetic pumps operation, two auxiliary objectives were considered. The first is related to the full exploitation of electromagnetic finite element models in order to retrieve as much information as possible about electromagnetic pumps behavior in a simplifying hypothesis that does not take into account the fluid dynamics. The second auxiliary objective is to build numerical models that couple the electromagnetism and the fluid dynamics, namely the two interdependent physics that govern the magnetohydrodynamic flow through channels of electromagnetic pumps.In the section dealing with the study of electromagnetic pumping of molten salts, the thesis highlights specific problems related the generation of electromagnetic forces in fluids with low electrical conductivity and provides results with respect to applications where electromagnetic pumping of molten salts can be effective. With the electromagnetic numerical models were obtained important data about the influence of the number of electromagnetic poles and supply frequency on the Pressure – Velocity characteristic of annular linear induction pumps. Were analyzed the shielding effect generated by the metallic walls - with negative repercussions on pumps performances, braking effects exerted at pump inlet and pump outlet and the connection between the overload capacity and Pressure – Velocity characteristic of induction pumps. A special portion was devoted to the analysis of the time and space dependence of the electromagnetic force and to the study of the non-uniformities of electromagnetic quantities in azimuth direction of annular linear induction pumps.In the chapter devoted to the magnetohydrodynamic interaction through coupled models, the thesis proposes two models that couple the electromagnetism and the fluid flow, one realized using multiphysic software and the second by coupling two different softwares. There are presented the advantages of the coupled models with respect to the results accuracy in comparison with electromagnetic models. It is presented the evolution of velocity, force and current densities profiles under the influence of the electromagnetic field and of different sodium mean velocities.The contributions of the thesis are completed with significant observations related to the study methods and software tools used along the study process
Preocupările actuale în legătură cu exploatarea în siguranță a centralelor nucleare existente și în legătură cu proiectarea arhitecturilor speciale de reactoare nucleare pentru generația a patra,coroborate cu interesul tot mai pronunțat pentru eficiența și fiabilitatea oricărui echipament dintr-un sistem energetic, fac ca tot mai multe demersuri de cercetare să se îndrepte spre studiul diverselor subansamble ale acestor sisteme pentru o mai buna înțelegere și optimizare pe baza mijloacelor moderne de proiectare asistată de calculator. Din rândul tipurilor propuse pentru generația a patra de reactoare nucleare fac parte și cele care au ca agent de răcire săruri topite, respectiv sodiu topit. Multe reactoare nucleare de generație anterioară folosesc ca mijloc de antrenare a fluidelor de răcire pompe mecanice de construcție specială. Sărurile topite ăi sodiul lichid, datorită proprietăților fizice,au potențialul de a fi recirculate cu ajutorul pompelor electromagnetice. Deși tehnologia pompării electromagnetice a fluidelor electroconductoare a fost dezvoltată încă din prima parte a secolului trecut, în prezent cunoaște o renaștere datorită reconsiderării multiplelor avantaje tehnologice și de securitate în exploatare. Lucrarea de față este atât un studiu al fenomenelor intime ce au loc ca urmare a curgerii fluidelor electroconductoare în câmpul electromagnetic al pompelor electromagnetice – interacțiune magnetohidrodinamică - cât și un raport despre capabilitățile și avantajele uneltelor moderne de calcul de a înlesni proiectarea și optimizarea pompelor electromagnetice. Pentru a atinge scopul principal al tezei, și anume o înțelegere mai adâncă a fenomenelor interdependente specifice funcționării pompelor electromagnetice, au fost considerate două obiective secundare. Primul obiectiv se referă la exploatarea la maximum a modelelor electromagnetice numerice în element finit cu scopul de a obține cât mai multe informații cu putință despre comportamentul pompelor electromagnetice în ipoteza care nu ia în considerare curgerea fluidelor. Al doilea obiectiv a fost construirea unor modele numerice care cuplează electromagnetismul și curgerea, respectiv, cuplează modelele numerice ale celor două fenomene ce caracterizează curgerea magnetohidrodinamică din canalele pompelor electromagnetice. În partea dedicată studiului pompării electromagnetice a sărurilor topite, teza evidențiază problemele specifice legate de generarea forțelor electromagnetice în fluide slab conductoare electric și oferă rezultate cu privire la aplicațiile unde pomparea electromagnetică a sărurilor topite poate fi eficientă. Cu ajutorul modelelor electromagnetice s-au obținut date importante despre influența numărului de poli electromagnetici și frecvența de alimentare asupra caracteristicii Presiune – Viteză a pompelor electromagnetice inelare de inducție. Au fost analizate fenomenul de ecranare creat de peretii metalici – cu repercursiuni negative asupra performanțelor pompelor, efectele de frânare exercitate la intrarea și la ieșirea din canalul de pompare și legătura dintre capacitatea de suprasarcină hidrodinamică și caracteristica Presiune – Viteză a pompelor de inducție. O secțiune specială a fost consacrată analizei dependenței de timp și a variației de la punct la punct a forței electromagnetice, precum și studiului neuniformităților mărimilor de natură electromagnetic în direcție azimutală în pompele inelare de inducție. În capitolul despre interacțiunea magnetohidrodinamică pe baza modelelor cuplate, se propun două modele ce cuplează electromagnetismul și curgerea fluidelor, unul realizat cu ajutorul unui singur software și al doilea realizat prin cuplarea a două software-uri diferite. Sunt prezentate avantajele modelelor cuplate din punctul de vedere al acurateței rezultatelor în comparație cu modelele electromagnetice …

Thesis (M.S.)--University of Georgia, 2005.
Directed by Joy B. Peterson. Includes an article submitted to International journal of systematic and evolutionary microbiology. Includes bibliographical references (leaves 73-79).

碩士
國立彰化師範大學
生物學系
107
Tool use by the nonhuman animals has been noticed and researched in recent decades. Compared to the most research about primates and Corvidae, only few researches about the formicidae. In the past, the tool used by ants mainly recorded by observation. Previously research indicate, Aphaenogaster senilis has the selectively preferences and flexibility about tool use. But the tool selection of foraging strategy between different colony size didn't have further investigate. In this research, we want investigated the tool selection of foraging strategy between different colony size in Aphaenogaster tipuna: (1) Does the different colony size have the different time to find the resource. (2) Does the first forager from the different colony size will has different time to take sugar water. (3) Does the first forager from the different colony size will has different behavior after taking sugar water. (4) Does the first forager from the different colony size will has different preferred choice about tool use (sponge, rock grains, soil grains, and leaf fragments), (5) Does the first forager from the different colony size will has different tool selection strategy. The result showed that A. tipuna worker could find the sugar water quickly, and all colony size preferred to recruitment their mate after taking sugar water. However, worker from the large colony size could spend less time taking sugar water than the small colony size. The worker from the large colony size preferred to use sponge than the other tools, but the worker from the small colony size has no obviously preferred about the tool use. These results indicate that A. tipuna has flexible tool selection of foraging strategy between different colony size.

Dissertação de Mestrado em Ecologia, apresentada ao Departamento de Ciências da Vida da Faculdade de Ciências e Tecnologia da Universidade de Coimbra.
Mais de metade da população mundial vive em zonas urbanas (54%) e é previsto um aumento neste valor num futuro próximo. O aumento da urbanização leva a uma maior pressão exercida sobre os cursos de água, resultando numa degradação fisico-quimica e ecológica, um fenómeno conhecido como “Urban Stream Syndrome”. Os macroinvertebrados aquáticos, especialmente os pertencentes a ordens mais intolerantes à poluição como os Ephemeroptera, Plecoptera e Trichoptera são muitas vezes usados como indicadores biológicos. Neste estudo avaliei durante 7 dias em experiências laboratoriais, a qualidade da água e alimento de um curso de água de pequena ordem usando os macroinvertebrados trituradores Leuctridae, Sericostomatidae e Tipulidae. Não houve efeito da água e alimento na sobrevivência dos macroinvertebrados. Excepto para os mais tolerantes (Tipulidae), as taxas de consumo do alimento proveniente do curso de água urbano foram maiores que as taxas de consumo do alimento proveniente do curso de água controlo, especialmente para os macroinvertebrados mantidos em água do curso de água urbano. Os resultados obtidos sugerem que a fraca qualidade do alimento, provavelmente devido a uma baixa colonização microbial e a degradação da qualidade da água, provavelmente devido a fontes de poluição não pontuais, impedem o estabelecimento destes trituradores intolerantes à poluição no curso de água em estudo.
More than half of the world’s population lives in urban zones (54%) and the value is expected to increase in a near future. The increase in urbanization led to increasing pressures on streams resulting in physicochemical and ecological degradation, a phenomenon known as the ’Urban Stream Syndrome‘. Aquatic macroinvertebrates, especially the more pollution intolerant orders Ephemeroptera, Plecoptera and Trichoptera, are often used as bioindicators. In this study I assessed, via 7 days laboratory experiments, the quality of water and food of a low order urban stream using the macroinvertebrate shredders Leuctridae, Sericostomatidae and Tipulidae. There was no effect of water or food quality in survival. Except for the more tolerant Tipulidae, consumption rates of urban food were higher than consumption rates of control food, especially for macroinvertebrates kept in urban water. The obtained results suggest that poor food quality, probably due to lower microbial colonization, and water quality degradation, probably due to non-point pollution sources, prevent the establishment of intolerant shredders in the stream