Дисертації з теми "Commensalismo"
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Angi, Barbara. "Strategie di sopravvivenza urbana, istruzioni per l'uso." Doctoral thesis, Università degli studi di Trieste, 2009. http://hdl.handle.net/10077/3144.
Повний текст джерелаNel mondo contemporaneo, i territori metropolitani presentano in larga misura fenomeni di instabilità urbana causati soprattutto da flussi migratori sempre crescenti, dovuti principalmente all’apertura delle frontiere e alla recessione economica. Questo fenomeno globale dovrebbe sollecitare la nostra disciplina a ricercare soluzioni abitative a costi ragionevoli e a tempo determinato. Nella realtà europea emerge un sistema-città che, nel suo insieme, non è definibile come entità data, certa, immutabile, sulla quale sovrapporre un nuovo disegno, è invece un sistema aperto in continua trasformazione, in perenne mutazione. Questo scritto parte dal presupposto che i modelli di intervento finora applicati per gestire il fabbisogno abitativo, o anche l’habitat minimo progettato per eventi calamitosi, possano ampliare i loro orizzonti verso nuove emergenze legate alle attuali esigenze sociali ed economiche di una sempre più considerevole porzione della popolazione. Lo spazio urbano è attraversato oggi da perenni flussi – di automobili, di persone, di informazioni – difficilmente gestibili con una pianificazione a lungo termine, ma solo limitatamente alla predisposizione di infrastrutture di collegamento dei sistemi urbani, la disciplina architettonica dovrebbe (potrebbe) assimilare la nozione di mutazione con la messa a punto di manufatti ad assetti variabili in grado di rispondere ad esigenze funzionali transitorie. La trattazione si sviluppa con l’intento di indagare quei fenomeni di modificazioni urbane temporanee che si collegano, non solo all’autogestione del territorio da parte del fruitore che costruisce, per necessità o spontaneamente, la propria casa, nonché di esaminare alcuni progetti teorici, in parte utopici e in parte futuribili degli ultimi cinquant’anni elaborati soprattutto da gruppi di avanguardia. Sono state indagate, pertanto, alcune micro realtà abitative connesse alla necessità di insediamento in contesti metropolitani in cui è difficile ritrovare il concetto di casa inteso come elemento di riconoscibilità geopolitica: fenomeni d’emergenza abitativa incontrollati, inseriti all’interno del tessuto urbano indifferentemente, innesti temporanei che compaiono e scompaiono velocemente, aggredendo qualsiasi porzione di spazio libero, dalle aree industriali dismesse, agli snodi infrastrutturali, ai centri storici fatiscenti. Ai limiti tra l’autocostruzione e la pratica dell’abusivismo, frequentemente, il tipo di rapporto che queste micro realtà instaurano con il tessuto urbano segue le regole parassitarie di vicendevole alleanza tra due insiemi biologici e garantisce la sopravvivenza di entrambi, ma su livelli diversi: quello legale, costituito da piani di sviluppo speculativi o in cui non esistono strumenti urbanistici efficaci e quello illegale, governato dall’esigenza di sopravvivere in condizioni metropolitane avverse. La richiesta di alloggi temporanei permette inoltre di considerare il costruito in maniera differente: scenario dove poter agganciare la casa, dove poter innestare l’habitat minimo in posizioni strategiche, innescando rapporti simbiotici tra l’esistente e l’innesto. Si tratta di fenomeni che, se analizzati criticamente, possono portare a conclusioni inedite. Proprio in Italia, paese nel quale poco si demolisce e molto si conserva, manipolazioni di questo tipo potrebbero rinnovare aree depresse o vaste zone industriali dismesse. Se si considera la residenza come efficace strumento di controllo sociale, i diversi gradi di simbiosi che si possono stabilire tra il costruito e gli innesti potrebbero generare risultati proficui sia sul piano economico ma soprattutto psicosociale degli utenti. L’architettura potrebbe scoprire una nuova espressività, una nuova scrittura, potrebbe nascere un’architettura virale che, come ci suggerisce Franco Purini, sia il risultato di una molteplicità di processi formali di tipo infettivo.
Nella prima parte si analizza una sezione della cultura architettonica europea che, nella seconda metà XX secolo, ha caratterizzato la ricerca disciplinare innescando un forte ripensamento sui mezzi e sulle finalità dell’architettura stessa, promuovendo modelli insediativi rivolti ad una società dotata di un alto grado di mobilità sociale. Fughe in avanti che sembrano sopite, ma dalle quali si possono ancora trarre utili insegnamenti – come dimostrano alcuni dei protagonisti dell’attuale dibattito architettonico globale – e ritrovare spunti di riflessione per gestire la complessità della metropoli contemporanea, concepita come modello dinamicamente e costantemente in evoluzione, in perenne accelerazione. Il pre-testo della ricerca affonda le radici nel saggio di Andrea Branzi Le profezie dell’architettura radicale, apparso nel volume Radicals a cura di Gianni Pettena del 1996. In esso Branzi definisce l’architettura radicale non tanto come «un movimento culturale preciso, piuttosto come un fenomeno energetico, un ‘territorio sperimentale’ che ha investito la cultura del progetto europeo tra gli anni Sessanta e gli anni Settanta». La ricerca tende ad individuare un filo rosso nel vasto dibattito sul tema dell’abitare radical attraverso la rilettura di alcuni frammenti che compongono le testimonianze del periodo, peraltro non ancora debitamente sistematizzate. Sono stati indagati avvenimenti e dibattiti del tempo, soprattutto in quei paesi in cui le lotte sociali hanno, senza alcun dubbio, condizionato le ricerche disciplinari. L’Italia, la Gran Bretagna, l’Austria e la Francia, tra il 1960 e il 1970, sono state considerate realtà rappresentative di condizioni in cui gli scontri ideologici legati all’esplosione della cultura di massa hanno prodotto sperimentazioni originali atte a rispondere alle trasformazioni sociali in atto, mettendo in discussione gli strumenti e le metodologie del progetto urbano e architettonico. I radicals, in ambito accademico prima e in quello professionale poi, hanno prodotto visioni di città future in cui l’uomo può liberamente muoversi in costruzioni dagli assetti variabili in grado di rispondere rapidamente alle richieste funzionali di un’utenza non più certa del proprio futuro ed in costante e continua evoluzione . Tra schizzi frettolosi, disegni ironici, fotomontaggi arditi prodotti nel periodo oggetto di indagine, sono stati selezionati alcuni studi sull’habitat minimo, fughe in avanti che tendevano a produrre oggetti, all’epoca, materialmente irrealizzabili ma divenuti oggi plausibili, in relazione alle opportunità fornite dallo sviluppo tecnologico, sia dal punto di vista costruttivo che funzionale.
Nella seconda parte, sono stati analizzati piccoli manufatti realizzati per aggiunta, per scavo, per manomissione del tessuto urbano contemporaneo, ponendo particolare attenzione a quelli di dimensioni abitative ridotte che, con la loro capacità di collaborare e/o di scontrarsi con pezzi di realtà costruita, si impastano con essa producendo inedite derive urbane. Operazioni di manipolazioni dell’esistente che coinvolgono principalmente due questioni: il limite da porre alla delirante espansione urbana e la riconversione ecologica dello stock edilizio contemporaneo prodotto, in particolar modo in Italia, durante il boom economico degli anni Cinquanta. Presa coscienza dell’impossibilità di operare con strategie edilizie che partano da un grado zero o che necessitino di modificare l’esistente in un ottica anti tabula rasa, sono stati privilegiati alcuni esempi campione che rielaborano e riarticolano il tessuto della città e dell’architettura, con scale d’intervento inattese, verosimilmente microscopiche. Nella contemporaneità si sono individuate due linee di ricerca che poggiano su presupposti simili e si sviluppano declinando scelte tecnologiche high o low tech. Da un lato, l’architettura rubata, fatta di micro inserimenti staminali innestabili sull’esistente, che producono soluzioni abitative legali, e dall’altro l’architettura dei rifiuti, fatta di oggetti di scarto, frutto della sovrabbondanza contemporanea di beni materiali, che vengono utilizzati per la costruzione di soluzioni abitative in territori illegalmente occupati. Entrambi gli approcci si legano a nuove o ritrovate esigenze d’uso dell’ambiente domestico e derivano sovente, dal parassitismo biologico, il concetto di mutazione. L’architettura della manipolazione o dell’innesto, può indicare alcune linee guida grazie alle quali operare in lembi urbani residuali tenendo conto della possibilità di variazione spontanea del costruito. Al di là degli evidenti aspetti di parassitismo connessi alle forme di sopravvivenza tipiche degli homeless, dei campi nomadi, delle conurbazioni improvvisate, delle favelas presenti in larga misura, ormai anche in Europa, ancor più interessante è rintracciare oggi metodologie costruttive parassitarie in tessuti urbani consolidati, legate a situazioni sociali connotate da preoccupanti fenomeni di precarietà economica. A conclusione della seconda parte sono state inserite, quasi a margine della trattazione generale, quindici schede sinottiche descrittive di progetti manifesto, di studi per piccole cellule, di esempi di habitat parassita, costruzioni inedite che, come sopra accennato, risultavano solo pochi lustri addietro carichi di componente utopica, sogni nei cassetti di giovani intellettuali vagheggianti mondi non sempre possibili. Queste microarchitetture risultano tuttavia oggi di grande attualità e addirittura fattibili con le tecnologie presenti sul campo. Ci sono apparsi pertanto come veri e propri riferimenti per altrettanti oggetti architettonici realizzati nella contemporaneità che, quasi provocatoriamente, sono stati accostati ai loro progenitori in questa piccola rassegna al fine di far meglio comprendere e cogliere criticamente il messaggio di un non lontano passato.
Nella terza parte sono documentati alcuni progetti, da me elaborati nel triennio, come strumenti di verifica degli assunti della ricerca: due concorsi internazionali sul tema dell’habitat minimo e gli esiti di un workshop didattico progettuale al quale ho partecipato in veste di tutor presso la Facoltà di Architettura di Trieste.
XXI Ciclo
1976
Storelli, Gilles. "Caractérisation de l’interaction mutualiste liant Drosophila melanogaster à son symbionte Lactobacillus plantarum." Thesis, Lyon, École normale supérieure, 2015. http://www.theses.fr/2015ENSL1041.
Повний текст джерелаSymbiotic bacterial populations (also called the “microbiota”) have a dramatic impact on their host’s physiology. However, our understanding of the mechanisms shaping host/microbes mutualism remains limited. We took advantage of Drosophila tractability to characterize the host’s and the microbial factors engaged in mutualism. During my PhD, I focused on the impact of the microbiota during the Drosophila larval phase, which constitutes its juvenile growth period. Drosophila larval phase is influenced by nutrition, but also by symbiotic microbes: specific association with the bacterium Lactobacillus plantarum buffers the deleterious effects of nutrient scarcity on the host’s juvenile growth, by sustaining greater growth rates and hastening maturation. L.plantarum mediate these effects by modulating the activity of the steroid hormone Ecdysone and the Insulin/Insulin-like Signaling pathway in its host. In return, L.plantarum benefits from Drosophila presence, as larvae ensure its long-term persistence in the niche (the niche being the nutritive substrate, the larvae and the bacteria dwelling on it). To characterize the mechanisms engaged in this mutualistic relationship, we described the host’s transcriptomic and metabolic responses to L.plantarum presence and characterized the metabolic perturbations occurring in the niche. Our results put forward the optimization of amino-acids extraction from the nutritive substrate as a cornerstone of mutualism. L.plantarum activates the expression of the host’s digestive proteases via IMD/NF-κB signaling and would benefit in return from an enhanced AA availability, which would help sustaining its long-term persistence. Altogether, our studies contribute to the understanding of the mechanisms regulating host/microbiota interaction and could lead to numerous therapeutic applications, notably aiming at counteracting the deleterious effects of nutritional imbalances
Grine, Ghiles. "Méthanogènes : entre commensalisme et opportunisme." Thesis, Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0623.
Повний текст джерелаIn the first part of our thesis, we reviewed the literature of all the methanogenic species found in the different microbiota of humans. We also reviewed the various methods used in clinical microbiology to research and identify these microorganisms. In a second part of our thesis, we have shown that the human digestive tract is colonized by M. smithii from the first day of life thus posing the question of potential sources of acquisition of this methanogen. We detected and isolated M. smithii and M. oralis in colostrum and breast milk suggesting mother-to-child contamination by breastfeeding. For vaginal specimens, M. smithii is detected in 97% of the samples collected from patients with bacterial vaginosis. Subsequently, we reported the detection of methanogens, M. oralis and M. smithii in the salivary fluid of individuals with no oral disease. In the third part of our thesis, we have shown for the first time that methanogens are part of the urinary microbiota in which we found M. smithii with a prevalence of 9%. Finally, we have optimized the methods of research and isolation of methanogens. We have developed a chemical method for producing H2. The expertise acquired and the results obtained during this thesis, invite us to continue research work in clinical microbiology of methanogens, questioning more particularly their roles in physiology and oral pathology
Defaye, Arnaud. "Etude des intéractions hôte-microbes chez la drosophile." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4047/document.
Повний текст джерелаBecause they are constantly exposed to contact with the various type of microorganisms present in their environment, multicellular organisms have evolved an immune system that allow them to sense their presence and control their growth. Close contact with these microbes naturally occurs in body parts that are exposed to the environment, like external body surfaces and internal mucosa, and at least two diffrerent kind of relations can be described. In the first case both the two parts do not harm the other, eventually allowing the relationship to go for a mutual benefit. In the second case, one part is agressive towards the other and lead it to induce a response to this stressful situation in order to preserve it's integrity and ultimately it's survival. From the host point of view, this response involves the immune system and most frequently aims at the eradication of the microbes. Using the fruitfly drosophila melanogaster as a model for the host side, i was interested in studying host-microbe interactions. A first project i worked on focused on drosophila circulating cells, the plasmatocytes, about which we knew some activities (secretion of cytokines, cloting factors, phagocytosis) but whose functional relevance to resist infection has never been tested. By generating plasmatocytes-depleted flies, I show that these cells are required for the survival of the adult upon some type of systemic bacterial infections, including Staphylococcus aureus and Salmonella typhimurium, but not all
Poreau, Brice. "Biologie et complexité : histoire et modèles du commensalisme." Phd thesis, Université Claude Bernard - Lyon I, 2014. http://tel.archives-ouvertes.fr/tel-01063917.
Повний текст джерелаHulme-Beaman, Ardern. "Exploring the human-mediated dispersal of commensal small mammals using dental morphology : Rattus exulans and Rattus rattus." Thesis, University of Aberdeen, 2014. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=215116.
Повний текст джерелаCucchi, T. "Le commensalisme de la souris et les sociétés néolithiques méditerranéennes." Phd thesis, Museum national d'histoire naturelle - MNHN PARIS, 2005. http://tel.archives-ouvertes.fr/tel-00363186.
Повний текст джерелаLa quantification de la variabilité actuelle des morphologies dentaires (analyses de Fourier) du genre Mus en Méditerranée a montré qu'il est possible de discriminer les espèces et sous-espèces du genre à partir du matériel fossile et qu'elle pouvait être un marqueur des flux géniques.
L'application archéozoologique nous a permis d'identifier l'émergence des pratiques de l'économie agricole néolithique (stockage des grains, champs cultivés...) au Proche-Orient comme le facteur déterminant dans l'adaptation de la souris à la niche commensale.
Enfin, nous avons montré que la souris domestique colonisa la Méditerranée occidentale lors de l'intensification conjointe des échanges et de l'urbanisation du premier millénaire av. J.-C., lui permettant de surmonter les barrières écologiques et génétiques qui, auparavant, empêchaient son invasion.
Cucchi, Thomas. "Le commensalisme de la souris et les sociétés néolithiques méditerranéennes." Paris, Muséum national d'histoire naturelle, 2005. https://tel.archives-ouvertes.fr/tel-00363186.
Повний текст джерелаWe aimed to determine the factors of the anthropisation involved in the mouse commensalism, using both phylogeographical and historical approaches. The quantification of the variability in the molar shape (Fourier analyses) of Mediterranean mice species showed that it is possible to separate species and sub-species of the genus using dental morphology and that this variability might be a marker of genes flow. Zooarchaeological analyses allowed us to identify the emergence of Neolithic farming practices (seeds storage, cultivated fields. . . ) in the Near East as the determining factor for the adaptation of the mouse to the commensal niche. Finally, we showed that the house mouse colonized the western Mediterranean during the intensification of both exchanges and urbanization in the first millennium BC, allowing it to overcome the ecological and genetic barriers which, previously, prevented its invasion
Ganem, Guila. "Commensalisme, fonction corticosurrénalienne et évolution chromosomique chez la souris domestique." Montpellier 2, 1991. http://www.theses.fr/1991MON20053.
Повний текст джерелаLackman-Ancrenaz, Isabelle. "Le commensalisme du babouin hamadryas (papio hamadryas hamadryas) en Arabie Saoudite." Paris, Muséum national d'histoire naturelle, 1998. http://www.theses.fr/1998MNHN0003.
Повний текст джерелаSood, Prashant. "Tools to study the transition from fungal commensalism to systemic infection." Thesis, University of Aberdeen, 2019. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=240695.
Повний текст джерелаAuffray, Jean-Christophe. "Le commensalisme chez la souris domestique : origine, écologie et rôle dans l'évolution chromosomique de l'espèce." Montpellier 2, 1988. http://www.theses.fr/1988MON20027.
Повний текст джерелаAuffray, Jean-Christophe. "Le Commensalisme chez la souris domestique origine, écologie et rôle dans l'évolution chromosomique de l'espèce /." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb376113537.
Повний текст джерелаBrault, Dominique. "Recherche d'un algicide sélectif approprié à la culture de Chondrus crispus (L. ) Stackh." Brest, 1985. http://www.theses.fr/1985BRES0013.
Повний текст джерелаDenou, Emmanuel. "Caractérisation préliminaire du commensalisme de Lactobacillus johnsonii dans l’intestin de la souris : du phénotype au génotype." Caen, 2006. http://www.theses.fr/2006CAEN2088.
Повний текст джерелаThe microbiota complexity in mammal gut seriously hampers the analysis of microbe-microbe and microbe-host interactions in situ. Microbes compete for colonization sites on the gut surface and for the use of food resources. At the same time, they cooperate in the digestion of complex food substrates, where the waste of one bacterium becomes the food of another bacterium. Currently, the relative contribution of competition and cooperation at the microbe/microbe interface is not well understood. The aim of this work was to explore the interaction of three common gut commensals, namely Escherichia coli, Lactobacillus and Bifidobacterium, which were jointly introduced into axenic mice. After determination of their anatomical distribution, the system was disturbed by the introduction of three other strains of Escherichia, Lactobacillus and Bifidobacterium. To obtain an idea about their physiological activity, we performed expression profiling analysis of B. Longum and Lb. Johnsonii along the different gut segments, and the results of this analys supported the nutrient niche theory. Moreover, an important task is to associate the in vivo phenotype, displayed by a bacterium in its ecological niche, with its genotype. Thus, genes affecting the intestinal residence time between two Lb. Johnsonii strains were targeted for analysis. We hypothesized that the underlying genes are specific for the long-persisting strain and are expressed during gut passage of the bacterium. Fusion of datasets from comparative genomic and in vivo expression profiling analysis identified three gene loci that were expressed in vivo and specific to the gut ecotype. Knock-out mutants were constructed for all three loci to investigate their involvement in the gut residence phenotype. The experiments revealed that the deletion of genes annotated as a sugar transporter and an IgA protease decreased the residence time, while a mutant with a deleted exopolysaccharide cluster showed an increased persistence time
Rice, Kevin Barry Eubanks Micky. "Mutualisms, commensalisms, and predation the direct and indirect effects of fire ants on arthropods and plants /." Auburn, Ala., 2007. http://hdl.handle.net/10415/1392.
Повний текст джерелаBarrett, Lauren Michelle. "Commensalism in yeast bacteria interactions: a study of the relationship between Metschnikowia pulcherrima and Oenococcus oeni." Master's thesis, ISA/UL, 2018. http://hdl.handle.net/10400.5/17933.
Повний текст джерелаThis research work addresses the under explored interaction between malolactic bacteria and non-Saccharomyces yeast, specifically commercial strains of Metschnikowia Pulcherrima and Oenococcus oeni. Chemically defined media and two chardonnay juices were used to evaluate sequential and co-inoculated malolactic fermentation strategies, investigating the effect of M. Pulcherrima on O. oeni viability and malolactic fermentation kinetics. L-malic acid consumption, and bacteria viability were tracked during fermentation, along with sampling for organic acid analysis. Our findings showed the addition of M. pulcherrima significantly influenced malolactic fermentation kinetics and increased O. oeni bacteria viability in chemically defined media, and select Chardonnay treatments. Further work is investigating the source of commensalism between M. pulcherrima and O. oeni. Exploring alternative strain pairs and understanding non- Saccharomyces and bacteria interactions will help increase winemakers control when implementing co-inoculation strategies for malolactic fermentation. This has a promising application in the industrial production of sparkling base wine, increasing malolactic fermentation efficiency and closing the gap for potential spoilage associated with conducting malolactic after alcoholic fermentation
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Carlotti, Arnaud. "Interaction "Candida kefir LY496 - levures autochtones" au cours de la production de biomasse de levure à partir de lactosérums bruts : sélection et optimisation d'une culture mixte." Lyon 1, 1990. http://www.theses.fr/1990LYO10175.
Повний текст джерелаSmati, Mounira. "Place de la structure génétique de l'espèce Escherichia coli dans l'état de son commensalisme intestinal et dans l'expression de sa virulence." Thesis, Paris 13, 2014. http://www.theses.fr/2014PA132041/document.
Повний текст джерелаEscherichia coli is the most abundant aerobic bacteria of the human microbiota, and a major opportunistic pathogen in humans. It is the clonal species for wich main phylogenetic groups have been described. The aim of this thesis is to study E. coli adaptation through the genetic structure of the specis in two circumstances : the intestinal comensalism, and the extra-intestinal virulence estimated via expression of genes encoding for yersiniabactin, a major siderophore, located on a high patogenicity island (HPI). The repartition of the 4 phylogroups has been studied in faecal microbiota of 100 humans and 137 animals thanks to an original quantitative PCR assay. Three main enterocolitypes, corresponding to associations of phylogroups, have been described. In humans, B2 phylogroup strains were exclusive in 15% of individuals and were shown to be clearly distinct from animal B2 strains on the base of the presence of two virulence factors (sfa/foc and pks). The impact of the genetic background of the B2 sub-groups II, III an IX on the virulence based on HPI was studied in a mice model and in an amoeba model Dictyostelium discoideum. The HPI interacts with the clonality of the species represented by the existence of the B2 subgroups
Hockenberry, Alyson Marie, and Alyson Marie Hockenberry. "Dissection of the Type IV Pilus Retraction Motor in Neisseria Gonorrhoeae." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/622992.
Повний текст джерелаFadlallah, Jehane. "Impact du déficit en IgA sur la symbiose hôte/microbiote intestinal chez l'homme." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066740/document.
Повний текст джерелаIgA responses play a key role in gut mucosa, defending host against pathogens but also shaping the commensal flora. In order to get insights into the specific contributions of IgA to host/microbial symbiosis in humans, we explored patients that lack only IgA, using gut microbial metagenomics and systems immunology. Microbiota composition was compared between 34 healthy controls and 17 selective IgA deficiency (sIgAd) patients. Contrary to what was observed in murine models of IgA deficiency, we show that human sIgAd is not associated with massive perturbations of gut microbial ecology, regarding phyla distribution, bacterial diversity and gene richness. A clear gut microbial signature is however associated to sIgAd: we found 19 over-represented MGS mainly described to be pro-inflammatory, but also 14 under-represented MGS, mainly known to be beneficial. We also explored local consequences of IgA deficiency, particularly whether IgM could replace IgA at host/bacterial interface. Using a combination of bacterial flow sorting and DNA sequencing, we therefore analysed the composition of IgM-coated microbiomes observed in sIgAd. We show that IgM only partially supply IgA deficiency, as not all typical IgA targets can also be opsonized by IgM, but nevertheless contribute to maintain Actinobacteria diversity. IgA deficiency is associated with a skewed circulating CD4+ T cell profile towards TH17, as well as markers of bacterial translocation. Finally, sIgAd is associated with a perturbation of the minimal bacterial network. Altogether our results suggest that human IgA deficiency is associated with a mild dysbiosis associated to systemic inflammation despite the presence of IgM
Mosher, Celeste V. "Commensalism and Reproductive Biology of the Brittle Star Ophiocreas oedipus Associated with the Octoral Metallogorgia melanotrichos on the New England Corner Rise Seamounts." Fogler Library, University of Maine, 2008. http://www.library.umaine.edu/theses/pdf/MosherCV2008.pdf.
Повний текст джерелаClark, Leisa Anne. "Butterbeer, Cauldron Cakes, and Fizzing Whizzbees: Food in J.K. Rowling's Harry Potter series." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4012.
Повний текст джерелаBrucker, Kaitlyn M. "An Endemic Commensal Leucothoid Discovered in the Tunicate Cnemidocarpa bicornuta, from New Zealand (Crustacea, Amphipoda)." NSUWorks, 2016. http://nsuworks.nova.edu/occ_stuetd/407.
Повний текст джерелаMerfield, Charles Norman. "Predator interactions within a trophic level : Phalangium opilio L. (Arachnida: Opiliones) and mites (Arachnida: Acari)." Master's thesis, Lincoln University. Bio-Protection and Ecology Division, 2000. http://theses.lincoln.ac.nz/public/adt-NZLIU20060908.204153.
Повний текст джерелаO'Connell, Heather Adele. "The Role of Ecological Interactions in Polymicrobial Biofilms and their Contribution to Multiple Antibiotic Resistance." Digital Archive @ GSU, 2006. http://digitalarchive.gsu.edu/biology_diss/13.
Повний текст джерелаSitterlé, Emilie. "La candidose cutanéo-muqueuse chronique : un modèle d’étude de l’adaptation génomique chez Candida albicans." Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCC275.
Повний текст джерелаCandida albicans is a common component of the human digestive tract and is considered the major opportunistic fungal pathogen. During interaction with the host, this yeast is confronted with numerous environmental and immune stresses imposing rapid adaptation capacities to survive. This manuscript aimed to study the genomic diversity of C. albicans, in healthy individuals and during long-term pathological interaction. In the first part of this work, we showed that there is a high level of genomic heterogeneity, especially linked to loss-of-heterozygosity, between isolates of C. albicans in oral samples from healthy carriers. Furthermore, we demonstrated that the heterogeneity observed is not reflective of technical problems nor associated to the high throughput sequencing data analysis. Then, we evaluated to which extent the C. albicans genome was able to evolve in a long-term pathological context, thanks to the study of chronological strains isolated from patients suffering from chronic mucocutaneous candidiasis. We have shown that there is an important dynamic in the appearance and the elimination of phenotypic and genotypic variants during the pathological interaction with the host. This may be the consequence of the adaptation of the strains to the chronic pathological interaction with its host. One of the interesting phenotype is the appearance of resistance to antifungal agents in these strains. An in-depth study of the genes involved in resistance to antifungal agents has enabled the detection and the description of new mutations in the ERG11 and TAC1 genes, involved in resistance to azole antifungals
Lalis, Aude. "Variabilité phénotypique et génétique des Mastomys (Rodentia, Muridae) de Guinée : évolution, environnement et infection virale." Paris 6, 2008. http://www.theses.fr/2008PA066613.
Повний текст джерелаCrenn, Klervi. "Interactions entre microalgues et bactéries dans l'environnement marin." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066110/document.
Повний текст джерелаMarine microalgal and bacterial contribution to the global biogeochemical cycles is largely recognized and lead to define them as key actors of oceanic ecosystems. In this context, it is essential to better understand the interactions occurring between bacteria and microalgae. In the marine environment, specific interactions between microorganisms require tight physical association that is made possible by cellular attachment. In this work, we first selected microalgae with physically attached bacteria. Two diatoms belonging to the genus Thalassiosira and Chaetoceros were selected to study the epibiotic microflora from long-term (microalgae in culture) and short-term (microalgae directly collected from natural communities) associations. This work highlighted strong similarities between epibiotic assemblages from long-term associations and a higher difference for epibiotic communities from short-term associations. The bacterial epibiotic assemblages were mainly composed of Alpha- and Gammaproteobacteria but also Bacteroidetes and Actinobacteria. This study also highlighted that the surface of microalgae represented a peculiar ecosystem where nearly half isolates constituted new taxa (genera and species). One of them representing a new genus has been completely characterized, contributing to the enrichment of the described bacterial diversity. Finally, the nature of interactions between diatoms and their epibiotic bacteria was analyzed by co-culturing to identify strong interactions, to be further examined by transcriptomics. Numerous commensal interactions have been identified, corresponding to the bacterial remineralization of organic matter. However, only small effects of bacteria on microalgal growth were observed. The experimental conditions that exclude a maximum of abiotic and biotic stresses may mask potential interactions that could occur in an unstable natural environment. These results reflect the complexity of biotic interactions, provide methods and model organisms to study them, and raise many exciting hypotheses for future work
Merfield, C. N. "Predator interactions within a trophic level : Phalangium opilio L. (Arachnida: Opiliones) and mites (Arachnida: Acari)." Diss., Lincoln University, 2000. http://hdl.handle.net/10182/21.
Повний текст джерелаBołtruszko, Joanna Sabina. "Skład gatunkowy i liczebność Rotifera z epizoonu wybranych małży z rodziny Unionidae." Phd thesis, 2014. http://hdl.handle.net/11320/1692.
Повний текст джерелаKażdy żywy organizm podlega interakcjom z innymi żywymi organizmami. Interakcje te odgrywają podstawową rolę w ewolucji biologicznej i pełnią główną rolę w funkcjonowaniu współczesnego świata. Przykładem związku jaki obserwujemy w przyrodzie, są zgrupowania drobnych organizmów zwierzęcych związane z powierzchnią ciała innego zwierzęcia. Zespół takich bezkręgowców, spędzających na gospodarzu część lub całe swoje życie, nazywamy epizoonem. Do organizmów epizoicznych należą także wrotki. Niewiele wiemy o epizoizmie wśród wrotków, a zależności między Rotifera i Bivalvia, nie były dotychczas przedmiotem zainteresowania rotiferologów. Badania nad epizoicznymi zespołami Rotifera zasiedlającymi powierzchnię muszli żywych małży mają wiec charakter pionierski. O ile bowiem doniesienia poświęcone występowaniu wrotków na jakichkolwiek żywych gospodarzach są nieliczne, to brak w literaturze informacji o epizoicznej faunie wrotków zasiedlającej małże. Celem prowadzonych badań było poznanie struktury gatunkowej oraz ekologii zespołów Rotifera związanych w swym występowaniu z powierzchnią muszli małży słodkowodnych. Ze względu na pionierski charakter badań należało stwierdzić czy małże są zasiedlane przez zespoły wrotków epizoicznych. Potwierdzenie istnienia takich zespołów umożliwiło sformułowanie kilku następujących hipotez badawczych: 1) Bivalvia posiadają specyficzne dla nich zespoły epizoicznych Rotifera, 2) gatunek gospodarza decyduje o strukturze zasiedlającego go zespołu epizoicznych wrotków, 3) charakter siedliska (limniczne versus lotyczne) ma wpływ na bogactwo gatunkowe i obfitość Rotifera bytujących na słodkowodnych małżach, 4) głębokość występowania gospodarzy ma znaczenie przy zasiedlaniu ich przez różne gatunki Rotifera, 5) w epizoonie małży występują gatunki wrotków nie spotykane lub rzadko spotykane w innych mikrosiedliskach. Zespoły epizoicznych Rotifera pobrano z dwóch rodzajów środowisk - lotycznego i limnicznego. Wytypowano osiem stanowisk na rzece Krutyni (Pojezierze Mazurskie), która charakteryzuje się naturalnym korytem i mało przekształconą zlewnią. Analizy siedlisk limnicznych dokonano w przybrzeżnej strefie jedenastu jezior północno - wschodniej Polski: Bartąg, Bartężek, Isąg, Kiełpińskie, Lekarty, Leleskie, Majcz Wielki, Rumian, Sarąg, Szymbarskie oraz Gorczyckie. O wyborze jezior decydowały: obecność małży z rodziny Unionidae, stopień izolacji geograficznej gospodarzy oraz brak połączenia między zlewniami jezior. Epizoon pobierany był z pięciu gatunków żywych małży należących do rodziny Unionidae (rząd Unionoida): Anodonta anatina (LINNAEUS, 1758), A. cygnea (LINNAEUS, 1758), Unio crassus PHILIPSSON, 1788, U. pictorum (LINNAEUS, 1758) i U. tumidus PHILIPSSON, 1788. Powierzchnia muszli oczyszczana była miękką szczoteczką a cały uzyskany osad po utrwaleniu analizowany był pod mikroskopem świetlnym. W zespołach epizoicznych wrotków obecnych na słodkowodnych małżach znaleziono 147 gatunków Rotifera z podgromady Monogononta oraz licznych przedstawicieli podgromady Bdelloidea. Najliczniej reprezentowanymi rodzajami były Lecane, Cephalodella i Trichocerca. Stwierdzono, że Bivalvia, jako duże bezkręgowce posiadają swoiste zoobionty, którymi są dwa gatunki wrotków - Lecane pumila i Wulfertia sp. - nie notowane dotąd w Polsce a znalezione na powierzchni muszli małży słodkowodnych, zarówno w środowisku lotycznym, jak i w limnicznym. Piętnaście gatunków wrotków: Cephalodella forficula, Collotheca balatonica, Colurella colurus, Lecane arcula, L. bifurca, L. flexilis, L lunaris, L. tenuiseta, Proalinopsis squamipes, Ptygura furcillata, P. melicerta, P. pilula, Testudinella truncata, Trichocerca taurocephala i T. weberi, wyraźnie preferowało przebywanie na powierzchni muszli, tworząc grupę gatunków zoofilnych. Gatunek gospodarza nie decydował o strukturze gatunkowej zasiedlającego go zespołu epizoicznych wrotków, choć została wyodrębniona grupa tzw. gatunków wyłącznych, charakterystycznych tylko dla jednego gospodarza i występujących na nim w jednym lub obu środowiskach. W środowisku limnicznym zanotowano niemal dwukrotnie więcej gatunków wrotków należących do gromady Monogononta, niż w środowisku lotycznym. W przypadku Monogononta, w obu typach środowiska zanotowano odmienną strukturę gatunkową występujących na powierzchni muszli zespołów. Każde ze środowisk charakteryzowało się odmiennym zestawem dominantów i gatunków osiągających wysoką frekwencję w zespołach epizoicznych. Badania nad wpływem głębokości występowania gospodarza na epizoiczne wrotki, wykazały brak zależności między głębokością i liczbą gatunków wrotków oraz ich zagęszczeniem. Zarówno liczba gatunków obecnych na powierzchni muszli małży, jak i podobieństwo faunistyczne między zespołami wrotków z obu badanych grup gospodarzy było zbliżone. Fauna wrotków na odmiennych głębokościach nie była ani zbyt oryginalna ani charakterystyczna wyłącznie dla płytkiego lub głębokiego litoralu. Na powierzchni muszli małży wystąpiły także gatunki wrotków uznawanych w Polsce za rzadkie, o mniejszej walencji ekologicznej. W obu typach środowiska znaleziono łącznie 32 takie gatunki. Trzech hipotez badawczych nie można było odrzucić. Pierwszej mówiącej o tym, że Bivalvia posiadają specyficzne dla nich zespoły epizoicznych Rotifera, gdyż wyodrębniono epizoiczne gatunki wrotków. Nie odrzucono też hipotezy mówiącej że charakter siedliska (limniczne versus lotyczne) ma wpływ na bogactwo gatunkowe i obfitość Rotifera bytujących na słodkowodnych małżach, gdyż w środowisku limnicznym zanotowano niemal dwukrotnie więcej gatunków wrotków należących do gromady Monogononta, niż w środowisku lotycznym. Trzecią hipotezą, której nie można było odrzucić jest ta, mówiąca o tym, że w epizoonie małży występują gatunki wrotków nie spotykane lub rzadko spotykane w innych mikrosiedliskach. Małże posiadają swoiste zoobionty, którymi są dwa gatunki wrotków -Lecane pumila i Wulfertia sp. - nie notowane dotąd w Polsce a znalezione na powierzchni muszli małży słodkowodnych, zarówno w środowisku lotycznym, jak i w limnicznym. Pozostałe dwie hipotezy należało odrzucić, gdyż ani gatunek gospodarza, ani głębokość nie miały wpływu na skład gatunkowy epizoicznych Rotifera.
Every living organism is subject to interactions with other living organisms. These interactions play a fundamental role in biological evolution and play a central role in the modern world. An example of a compound as observed in nature, small clusters are associated with the other animal body surface. Organisms that spend on the surface of another animal part or all of their lives are called epizoic. Epizoic organisms are also rotifers. Little is known about epizoism of rotifers and the relationship between Rotifera and bivalves have not been the subject of scientists interest. Research on epizoic Rotifera colonizing the surface of the shells of live bivalves are so pioneering. While the reports devoted to the occurrence of rotifers to any living hosts are scarce, in the literature is the lack of information about epizoic rotifer fauna inhabiting the mussels of freshwater bivalves. The aim of this study was to investigate the structure of the species and ecology Rotifera related to its occurrence on surface of freshwater bivalve. Due to the pioneering nature of the research should determine if the bivalve are populated by community of epizoic rotifers. Confirmation of the existence of such communities has enabled the formulation of several of the following hypotheses: (1) bivalves have their specific epizoic communities of Rotifera, (2) the species of the host determines the structure inhabit it epizoic rotifers, (3) the nature of the habitat ( limnic versus lotic ) has an impact on species richness and abundance of Rotifera on freshwater bivalves, (4) the depth of occurrence of the host is important in colonization them by various species of Rotifera, (5) epizoic species of rotifers on bivalves are not common or rare in other microhabitats. Epizoic communities of Rotifera were collected from two types of environments - lotic and limnic. On the Krutynia River (Masurian Lake District) which is characterized by a natural streambed and little transformed basin, were selected eight sampling sites. Analysis of limnic habitat was made in the coastal zone of the eleven lakes in the north - eastern Poland: Bartąg, Bartężek, Isąg, Kiełpińskie, Lekarty, Leleskie, Majcz Wielki, Rumian, Sarąg, Szymbarskie and Gorczyckie. The choice of lakes was determined by the presence of bivalves from the family Unionidae, the geographic isolation and lack of connections between the basins of lakes. Epizoon was collected from five species of bivalve belonging to the family Unionidae (category Unionoida): Anodonta anatina (Linnaeus, 1758), A. cygnea (Linnaeus, 1758), Unio crassus Philipsson, 1788, U. pictorum (Linnaeus, 1758) and U. tumidus Philipsson 1788. Shell surface was cleaned with a soft brush and the resultant precipitate was analyzed after fixation under a light microscope. The epizoic rotifers communities present on freshwater bivalves found 147 species of Rotifera of the subdivision Monogononta and many in subdivision Bdelloidea. Most well-represented types were Lecane, Cephalodella and Trichocerca. It was found that bivalves, as large invertebrates have specific zoobionts, which are two species of rotifers - Lecane pumila and Wulfertia sp - not traded so far in Poland and found on the surface of the freshwater bivalves in both the lotic as well as limnic habitat. Fifteen species of rotifers: Cephalodella forficula, Collotheca balatonica, Colurella colurus, Lecane arcula, L. bifurca, L. flexilis, L. lunaris, L. tenuiseta, Proalinopsis squamipes, Ptygura furcillata, P. melicerta, P. pilula, Testudinella truncata, Trichocerca taurocephala and T. weberi clearly have preferred staying on the surface of the shell, forming a zoophilic species. Host species not determined the structure of their epizoic rotifers community, although was spun exclusive group of species characteristic for only one host and found in one or both types of habitat. In limnic habitat recorded almost twice as many species of rotifers belonging to the Monogononta than lotic habitat. For Monogononta, in both types of habitat different species structure was observed on the surface of the shell. Each of the habitat characterized by a different set of dominant species and achieving high turnout in epizoic community. Studies on the influence of the depth of occurrence of the host of epizoic rotifers showed no relationship between depth and number of species of rotifers and their density. Both the number of species present on the surface of the shells of bivalves as well as faunal similarity between the rotifers communities of both groups was similar. Rotifers at different depths was neither very original nor a characteristic only for shallow or deep littoral. On the surface of bivalves observed species of rotifers also recognized in Poland as rare, with less ecological valence. In both types of habitat found a total of 32 such species. Three hypotheses could not be rejected. First speaks that bivalves have their specific epizoic rotifer community. The second not rejected hypothesis was that the nature of the habitat (limnic versus lotic) has an impact on species richness and abundance of Rotifera on freshwater bivalve as in the limnic habitat recorded almost twice as many species of rotifers belonging to the Monogononta than lotic habitat. The third hypothesis, which could not be rejected is the one talking about the fact that in epizoic species of rotifers are not common but rare in other microhabitat. Bivalve have a specific zoobiont, which are two species of rotifers - Lecane pumila and Wulfertia sp - not listed so far in Poland and found on the surface of the freshwater bivalves, in both the lotic as well as limnic habitat. The other two hypotheses had to be rejected because neither host species, nor depth had no effect on the epizoic Rotifera species composition.
Kaftanová, Barbora. "Myš, potkan, krysa: prostor, pach a metody detekce." Doctoral thesis, 2018. http://www.nusl.cz/ntk/nusl-388553.
Повний текст джерелаŠtolhoferová, Iveta. "Vliv synantropie na vertikální aktivitu v exploračních testech: srovnání 12 populací rodu Acomys." Master's thesis, 2019. http://www.nusl.cz/ntk/nusl-405717.
Повний текст джерелаKimbrel, Jeffrey A. "Genome-enabled discovery and characterization of type III effector-encoding genes of plant symbiotic bacteria." Thesis, 2012. http://hdl.handle.net/1957/28344.
Повний текст джерелаGraduation date: 2012
Baía, Inês Sofia Lima. "Mechanisms Shaping Intra-species Interactions in Streptococcus pneumoniae." Master's thesis, 2022. http://hdl.handle.net/10362/131998.
Повний текст джерелаStreptococcus pneumoniae (pneumococo) coloniza assintomaticamente o trato respiratório superior humano. Em algumas circunstâncias o pneumococo causa infeções que estão associadas a uma elevada morbilidade e mortalidade a nível mundial. A colonização simultânea por mais de uma estirpe de pneumococos é frequente, criando oportunidade para estas interagirem. Estas interações parecem ser importantes para a evolução da população pneumocócica. Assim, o estudo das interações que ocorrem é importante para compreender a dinâmica de colonização e avaliar o impacto das vacinas. Um estudo realizado previamente pelo grupo, identificou interações entre estirpes de pneumococos num modelo in vitro de biofilme. Nesse estudo identificaram-se duas interações fortes: i) uma interação de amensalismo em que a estirpe 1990-19F inibiu a estirpe 7031-NT; e ii) uma interação de comensalismo em que a estirpe 5435-NT beneficiou ao crescer com a estirpe 7632-15A. Esta tese teve como objetivo identificar os mecanismos moleculares que modelam as interações acima descritas. Nas experiências realizadas utilizaram-se variantes das estirpes marcadas com GFP ou RFP (green ou red fluorescente protein, respetivamente) que permitiram a contagem de células e a distinção entre estirpes por citometria de fluxo em experiências com co-culturas. A interação de amensalismo foi também detetada em culturas planctónicas. Identificou-se que a interação deverá ser mediada por uma proteína secretada, possivelmente em conjunto com outros fatores. Observou-se que o fratricídio induzido por competência (mediado por efetores proteicos), alterações de pH ou diferenças nos padrões de crescimento das duas estirpes não são determinantes para a interação. A interação de comensalismo não foi consistente em crescimento planctónico. Através de um ensaio transwell, identificou-se que esta deverá ser dependente de contacto celular. Observou-se que a cápsula 15A poderá ser importante para a interação. Em conclusão, este trabalho permitiu identificar potenciais mecanismos mediadores de interações de amensalismo e comensalismo entre estirpes de pneumococos.