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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.
11

Variations in the Invertebrate Communities of Wild Cape Cod Cranberry Bogs

Wagner, Barbara 23 March 2016 (has links)
As a species domesticated only in the last century, agricultural cranberry plants (Vaccinium macrocarpon) remain little removed from their wild relatives. Thus, it is a potential model species for studies of the earliest stages of domestication; however, there is little available quantitative information on its wild population biology and ecology. As such information is vital to studies of the ecological changes occurring during domestication, the purpose of this study was to consolidate the relevant knowledge available and conduct a preliminary search for patterns in the invertebrate communities of wild bogs. The alpha diversity was found to be greater than the overall (gamma diversity), which is likely a result of the metric used and the fact that there was minimal overlap in rare species between bogs. In addition, alpha diversity was found to be significantly negatively correlated with bog age. Two pairs of species were found to be correlated with each other, Blunt-nosed (Limotettix vaccinia (Van Duzee)) and Sharp-nosed leafhopper (Scaphytopius sp.), along with fleabeetle (Sysena frontalis (F.)) and firebeetle (Cryptocephalus incertus (Oliv.). In addition, it was found that spiders are significantly more common in western bogs, while firebeetle is significantly more common in eastern bogs. However, this may be indicative of a correlation with bog age rather than a true correlation with geographic location. More work is needed to determine the true dynamics driving these findings, so that the information could eventually be used to improve the efficacy and decrease the environmental impact of pest management on agricultural bogs.
12

Caracterización y mejora genética de la berenjena (Solanum melongena) para compuestos bioactivos

Plazas Ávila, María de la O 31 March 2015 (has links)
Tesis por compendio / Las frutas y hortalizas presentan compuestos bioactivos beneficiosos para la salud humana. El desarrollo de variedades con un mayor contenido en este tipo de compuestos es de interés, ya que contribuye a satisfacer una demanda creciente por parte de los consumidores por productos con propiedades funcionales. Dentro de las hortalizas, la berenjena (Solanum melongena) presenta una alta actividad antioxidante, fundamentalmente derivada de su alto contenido en polifenoles, y se ha demostrado que presenta efectos beneficiosos para la salud humana. Entre los compuestos fenólicos de la berenjena destaca el ácido clorogénico, ya que se trata del más abundante en este cultivo y presenta múltiples propiedades beneficiosas para la salud. Esta Tesis Doctoral trata de la caracterización y mejora de la berenjena para obtener información relevante y material vegetal para el desarrollo de variedades de berenjena con un mayor contenido en compuestos bioactivos, en particular polifenoles. Para ello utilizamos la variación intraespecífica e interespecífica. Por otra parte, en una mejora integral se debe tener en cuenta no solo el carácter a mejorar, sino también aquellos caracteres de interés para el éxito de una variedad, por lo que también hemos estudiado otros caracteres relacionados con el incremento del contenido en polifenoles, como puede ser el pardeamiento del fruto, y así como otros caracteres de interés general en mejora. En una primera parte de esta Tesis Doctoral nos centramos en el estudio de la diversidad en berenjena común y especies relacionadas para los caracteres objeto de esta tesis y también para caracteres de interés agronómico. El objetivo es evaluar la diversidad, identificar fuentes de variación y estudiar las relaciones entre caracteres. En un primer estudio, evaluamos una colección de variedades tradicionales de berenjena, en la cual hemos encontrado una alta diversidad para caracteres de calidad funcional y pardeamiento. En este estudio encontramos que el contenido en ácido clorogénico está correlacionado positivamente con la actividad antioxidante y que la correlación con el pardeamiento es baja, demostrando que es posible seleccionar variedades de berenjena con alto contenido en ácido clorogénico y pardeamiento moderado. También comprobamos que incluso con baja actividad polifenol oxidasa (PPO) se puede producir pardeamiento significativo, sugiriendo que la actividad PPO no es el factor limitante para el pardeamiento en la colección estudiada. Con objeto de ampliar la diversidad genética de la berenjena para la mejora de compuestos bioactivos y otros caracteres de importancia hemos estudiado la diversidad en una colección de berenjenas escarlata (S. aethiopicum) y gboma (S. macrocarpon). La caracterización morfológica mediante descriptores convencionales y herramientas fenómicas (Tomato Analyzer) nos ha permitido estudiar las relaciones entre los distintos grupos de cultivares y especies silvestres relacionadas y determinar que los complejos berenjena escarlata y gboma son hipervariables. En esta colección hemos estudiado también la actividad reductora y el contenido en ácido clorogénico, encontrado una enorme variabilidad. En general, la berenjena escarlata presenta contenidos relativamente bajos, mientras que la berenjena gboma, en particular su ancestro silvestre S. dasyphyllum, presentan valores muy elevados. También hemos comprobado en cultivos celulares de macrófagos que las variedades con mayor contenido en ácido clorogénico presentan una mayor inhibición de la producción de óxido nítrico (NO) indicando propiedades beneficiosas para la salud. En la segunda parte de la Tesis Doctoral hemos evaluado el interés de la hibridación interespecífica para la mejora de la berenjena, en particular para el contenido en compuestos bioactivos. Hemos obtenido dos familias, incluyendo retrocruzamientos, entre la berenjena común (S. melongena) por una parte y la berenjena escarlata cultivada (S. aethiopicum) y la especie silvestre S. incanum por otra. Los resultados muestran que la fertilidad de los materiales derivados de la hibridación entre S. melongena y S. aethiopicum es baja y que se obtiene una baja eficiencia en los retrocruzamientos hacia S. melongena. Además, el bajo contenido en polifenoles de S. aethiopicum se comporta como dominante. En cambio el retrocruzamiento hacia S. aethiopicum proporciona muchas plantas con mayores niveles de fertilidad. Sugerimos, por tanto, que S. melongena puede ser una fuente de variación para la mejora en contenido en polifenoles de la berenjena escarlata. La familia obtenida por hibridación interespecífica entre S. melongena y S. incanum mostró altos niveles de fertilidad y en el primer retrocruce hacia S. melongena se encuentran individuos morfológicamente similares a la Resumen berenjena cultivada. El estudio de los compuestos fenólicos mostró que S. incanum es una buena fuente de variación para la mejora de la berenjena común, con valores muy superiores a los de la especie cultivada. En el primer retrocruce se encuentran ya individuos con alto contenido en ácido clorogénico y pardeamiento moderado, lo cual sugiere que es posible introgresar exitosamente el alto contenido en ácido clorogénico de S. incanum en el fondo genético de la berenjena cultivada. En definitiva, los trabajos realizados en esta Tesis Doctoral aportan nuevo conocimiento sobre la diversidad y relaciones entre caracteres implicados en la calidad funcional de la berenjena y otros caracteres de interés en la mejora genética de este cultivo. Los materiales seleccionados y obtenidos son de gran interés para el desarrollo de variedades comerciales de berenjena con propiedades bioactivas mejoradas. / Plazas Ávila, MDLO. (2015). Caracterización y mejora genética de la berenjena (Solanum melongena) para compuestos bioactivos [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/48563 / Compendio
13

Caractérisation moléculaire des micro-organismes endophytes de la canneberge (Vaccinium macrocarpon Ait.)

Salhi, Lila Naouelle 04 1900 (has links)
Il a été établi que la majorité des plantes vasculaires abritent des micro-organismes endophytes bactériens et fongiques, qui peuvent coloniser les tissus végétaux et former des associations allant du mutualisme à la pathogénèse. Les symbioses végétales mutualistes les plus communes impliquent les champignons endo-mycorhiziens arbusculaires (AMF). Ces champignons s’associent aux racines des plantes et leur permettent d’améliorer leur nutrition minérale, tandis qu’ils bénéficient des composés produits par l'hôte. Toutefois, les plantes de la famille Ericaceae s’engagent plutôt dans des associations mutualistes avec les champignons mycorhiziens éricoïdes (ErMF). Ces derniers sont morphologiquement et taxonomiquement mal définis, en apparence distribués aléatoirement parmi les espèces issues des grandes divisions taxonomiques des Ascomycota et Basidiomycota. En raison de cette incohérence taxonomique et de l'absence d'une histoire évolutive explicative, la diversité réelle de ces champignons est mal caractérisée. De ce fait, ce projet vise à étudier le microbiote associé à la plante Ericaceae Vaccinium macrocarpon Aït (canneberge), axant la recherche sur les angles morphologiques, génomiques et transcriptomiques des champignons de type ErMF et autres endophytes capables de contrôler la croissance des agents phytopathogènes et de stimuler la croissance des plantes. Notre première démarche présentée dans le chapitre 2 s’est focalisée sur la caractérisation du microbiote endophyte bactérien et fongique de la canneberge, une plante vivace principalement produite en Amérique du Nord, notamment au Québec. Nous avons isolé et identifié 180 micro-organismes à partir de plantes de cultivars variés, collectées de champs différents, et avons démontré l'existence d'une variabilité dans le microbiote selon les tissus, les cultivars, et même entre les champs d'une même ferme. Parmi les endophytes d’intérêt identifiés, l’isolat fongique Lachnum sp. EC5 a stimulé la croissance des cultivars de canneberge Stevens et Mullica Queen et a formé des structures intracellulaires similaires à celles des ErMF à l’intérieur des cellules racinaires de la canneberge. De plus, l’isolat EB37 identifié Bacillus velezensis s’est révélé être un puissant agent antifongique, montrant cependant une tolérance particulière au champignon Lachnum sp. EC5, lors des tests de confrontation. Ce volet sera détaillé avec plus de précision dans le chapitre 4. Le chapitre 3 a porté sur l’analyse génomique comparative de l’isolat fongique Lachnum sp. EC5 avec plusieurs espèces de champignons Leotiomycetes ErMF, saprophytes et pathogènes. Nous avons analysé le sécrétome protéique prédit de ces champignons et mis en évidence que les gènes codant pour les enzymes de dégradation des parois végétales ne sont pas corrélés au mode de vie fongique (mycorhizien, pathogène ou saprophyte). A l’inverse, 10 protéines effectrices de Lachnum sp. EC5 prédites pour cibler spécifiquement un compartiment intracellulaire chez les cellules végétales ont des similarités avec celles d’espèces mutualistes comme Meliniomyces variabilis et Oidiodendron maius. Aussi, la protéine effectrice putative Zn-MP, prédite pour cibler, potentiellement, les chloroplastes végétaux nous permet de proposer un rôle dans le renforcement de l’immunité végétale. Le chapitre 4 s’est intéressé aux mécanismes de régulation d'expression de gènes induits lors de l’interaction entre le champignon Lachnum sp. EC5 et la bactérie B. velezensis EB37. Ces mécanismes ont été comparés à ceux activés chez la bactérie en présence de champignons pathogènes. Nous avons démontré une physiologique cellulaire bactérienne distincte en présence de Lachnum sp. EC5, dénotée par une faible expression des gènes induits lors du stress nutritif associé aux processus de sporulation, de formation du biofilm, de secretion de CAZymes et de lipopeptides. Nous avons suggéré que la sous-régulation de ces mécanismes serait essentiellement explicable par une disponibilité plus importante en glucose ou en d’autres sources de carbone préférentielles pour la bactérie. En réponse, le champignon Lachnum sp. EC5 a vécu différents changements morphologiques. Il aurait détoxifié ses environnements intra et extra-cellulaires et surexprimé sa voie de production de carbone dépendante du cycle du glyoxylate, générant ainsi des conditions favorisant un contact physique entre les deux micro-organismes. En conclusion, nous avons argumenté et documenté que la définition des ErMF basée uniquement sur des critères morphologiques est mal adaptée à catégoriser ces champignons. Notre approche multidisciplinaire a mis en évidence la diversité du microbiote de la canneberge, a étendu la notion d’ErMF à d'autres champignons jusqu'ici exclus de ce groupe, et a souligné l'importance des associations interspécifiques sur l’interaction ErMF-plantes. Ces avancées permettront d’améliorer nos connaissances sur le microbiote des plantes éricacées contribuant, au développement de solutions environnementales éco-responsables pour l’industrie de la canneberge. / It has been established that the majority of vascular plants harbour bacterial and fungal endophytes that colonize plant tissues, and thus form associations that range from mutualism to pathogenesis. Mycorrhizal fungi are a particular class of endophytes that associate with plant roots and enhance plant mineral uptake. The most common type of mutualistic plant symbiosis involves arbuscular mycorrhizal fungi (AMF), whereas plants of the Ericaceae family instead engage in mutualistic associations with ericoid mycorrhizal fungi (ErMF). The ErMF group, in its current definition, includes both ascomycete and basidiomycete species, yet is morphologically, taxonomically and evolutionarily poorly defined, which implies that the group’s true diversity is not well understood. The objective of this project is to complement morphological information with genomic and transcriptomic data to better understand the role of ErMF in 1) controlling the negative effects of pathogenic infections, and 2) the potential plant growth stimulation for the Ericaceous plant Vaccinium macrocarpon Ait. Our first approach presented in Chapter 2 focused on the characterization of the bacterial and fungal endo-symbiotic microbiota of the Ericaceous plant, Vaccinium macrocarpon Ait (cranberry), a perennial plant mainly in North America, particularly in Quebec. We isolated ~180 distinct bacterial and fungal endophytes collected from roots, stems, and leaves of cranberry plants cultivated in Quebec, Canada. We show that the cranberry microbiome varies substantially between tissues, cultivars, and across fields of the same farm. Among the isolated endophytes, the fungus Lachnum sp. EC5 was found to promote the growth of cranberry cultivars Stevens and Mullica Queen, and to form intracellular structures resembling those other ErMF inside the cortical root cells. In addition, the bacterium Bacillus velezensis (EB37) has been found to be a potent antifungal agent. Interestingly, a confrontation test between EB37 and the fungus Lachnum sp. EC5 revealed a mutual tolerance, which we will describe later in chapter 4. In chapter 3, our project focused on the comparative genomic analysis of the fungus Lachnum sp. EC5 with several Leotiomycete ErMF, saprophytes and pathogens. We analyzed fungal secretomes and demonstrated that genes encoding plant cell wall degradation enzymes are conserved between the tested fungi which suggests that such proteins are not indicative of a particular fungal lifestyle. On the other hand, 10 effector proteins identified in Lachnum sp. EC5 were also only found in mutualistic fungi, such as Meliniomyces variabilis, Oidiodendron maius and have been reported to target the plant intracellular compartments. Also, the identification of the putative effector protein Zn-MP, specific to Lachnum sp. EC5 and predicted to target plant chloroplasts, suggest a role in the reinforcement of plant immunity. Chapter 4 focuses on the patterns of gene expression regulation induced in the biocontrol bacterium B. velezensis EB37 in interaction with the potentially mutualistic fungus Lachnum sp. EC5. These mechanisms were then compared to those activated when the bacterium is in the presence of pathogenic/saprophytic fungi. We demonstrated that in co-culture with Lachnum sp. EC5, EB37expresses fewer genes related to stress, and fewer related to the stationary phase which often involves production of bacterial biofilms and lipopeptides, such as mycosubtilin. We suggest that the lessened response to stress is related to an increased availability of glucose or other preferential sources of carbons for the bacterium. Conversely, Lachnum sp. EC5 in the presence of EB37 underwent morphological changes by a higher lateral branching., detoxified its external and internal environment by expressing both a catalase activity and efflux pumps, and overexpressed its glyoxylate cycle-dependent carbon production pathway, and thus promoting favourable conditions for close physical contact with the bacterium. In conclusion, we demonstrated that the morphological-based definitions are poorly adapted to the categorization of ErMF fungi. Our multidisciplinary approach highlighted the diversity of the cranberry microbiota, extended the notion of ErMF to other fungi hitherto excluded from this fungal group and underlined the importance of interspecific associations on the ErMF-plant interaction. These advances enhance our understanding of the Ericaceous plant microbiota and contributes to the development of sustainable solutions for the cranberry industry.
14

Evidências científicas sobre o uso de plantas medicinais e avaliação do extrato de cranberry (Vaccinium macrocarpon) na pancreatite aguda experimental / Scientific evidence regarding the use of medicinal plants and evaluation of cranberry extract (Vaccinium macrocarpon) in experimental acute pancreatitis

Santana, Danielle Gomes 20 February 2017 (has links)
Acute pancreatitis (AP) is an inflammatory condition of the pancreas, which causes high mortality in the severe forms. Although the incidence of AP is increasing in the last years, there is no specific treatment for this condition. Preclinical evidence suggests that medicinal plants (MP) may be a viable alternative for the treatment of AP. The standardized extract of Vaccinium macrocarpon (SeVm) possesses antioxidant activity and may be useful in the treatment of this disease. The objetives of this study were to carry out a systematic review regarding the use of MP in preclinical models of AP and to investigate the anti-inflammatory, antioxidant and antinociceptive properties of SeVm in a model of AP in mice. Therefore, pre-clinical studies of AP in which a MP was administered and outcomes were compared to a control group (placebo treatment) were selected. Electronic searches were conducted using MEDLINE via PubMed, SCOPUS, Web of Science and Embase, and gray literature (Google Scholar) and hand search by using specific keywords. Two independent reviewers identified the relevant studies, extracted data and evaluated the risk of bias following the Systematic Review Protocol for Animal Intervention Studies (SYRCLE) risk of bias tool. Data from eligible studies were qualitatively extracted and synthesized. Thirty-one studies were selected, analyzed, and from these studies we concluded that the treatment with MP can be effective to treat experimental AP. For the experimental study, AP was induced in male Swiss mice (30-35 g, n=6 per group) by two successive injections of L-arginine (4 g/kg, i.p.), and euthanized 72 h after induction. Animals were treated with SeVm (50, 100 and 200 mg/kg, p.o.), dexamethasone (5 mg/kg, s.c.), morphine (5 mg/kg, i.p.), or vehicle (NaCl, 0,9%) every 24 h, starting from 1 h after the induction of AP. After euthanasia, inflammatory parameters (myeloperoxidase activity and concentration of tumoral necrosis factor [TNF]-α, interleukin [IL]-1β and IL-6 in pancreas and lung tissues, leucocyte counts in blood and edema index in pancreas), oxidative stress markers (thiobarbituric acid reactive substances [TBARS], non-protein sulfhydryl groups content [NPSH], carbonyl radicals content and ferric reducing/antioxidant power [FRAP] assay in lung and pancreas), antioxidant enzyme activities (catalase [CAT], superoxide dismutase [SOD] and glutathione peroxidase [GSH-Px] in pancreas and lung), biochemical parameters (concentration of amylase, lipase, alanine aminotransferase, aspartate aminotransferase, urea and creatinine in serum) and abdominal hyperalgesia were measured. The induction of AP by L-arginine significantly altered inflammatory parameters and oxidative stress markers, as well as abdominal hyperalgesia induced by AP. Treatment with SeVm inhibited the abdominal hyperalgesia caused by AP. All inflammatory parameters were reduced in animals treated with SeVm. Treatment with SeVm partially decreased the alterations in biochemical parameters in serum. The reduction of SOD and CAT activities in pancreas and lung of animals with AP, were reverted by the treatment with SeVm, but the activity of GSH-Px was not changed. The formation of TBARS and carbonil radicals were reduced after treatment with SeVm and the NPSH was increased after this treatment, as well as did total antioxidant potential. In summary, these results demonstrate that MP have potential in the treatment of experimental AP and that SeVm decreases inflammation, oxidative stress and hyperalgesia in AP, making it of interest in future approaches to treat this condition. / A pancreatite aguda (PA) é uma condição inflamatória do pâncreas que pode causar elevada mortalidade nas suas formas graves. Evidências pré-clínicas sugerem que as plantas medicinais (PM) podem ser uma alternativa viável para o tratamento da PA. O extrato padronizado da Vaccinium macrocarpon (EpVm) possui atividade antioxidante e pode ser útil no tratamento desta doença. Os objetivos deste estudo foram realizar uma revisão sistemática sobre o uso de PM em modelos pré-clínicos de PA e investigar as propriedades anti-inflamatória, antioxidante e antinociceptiva do EpVm em modelo de PA em camundongos. Para tanto, foram selecionados estudos pré-clínicos de PA em que PM foram utilizados e os desfechos foram comparados ao grupo controle (tratamento placebo). As buscas eletrônicas foram realizadas utilizando-se das bases MEDLINE, LILACS, BVS, SCIELO, SCOPUS, Web of Science e Embase, além da “gray literature” (Google Scholar) pela inserção de descritores e por “hand search”. Dois revisores independentes identificaram os estudos relevantes, fizeram a extração dos dados e avaliaram o risco de viés dos estudos selecionados, por meio da ferramenta de risco de viés do “Systematic Review Protocol for Animal Intervention Studies” (SYRCLE). Os dados dos estudos elegíveis foram extraídos e sintetizados qualitativamente. Trinta foram selecionados, analisados e a partir dos mesmos, foi possível concluir que o tratamento com PM pode ser efetivo na PA experimental. Para o estudo experimental, foi realizada a avaliação da capacidade antioxidante do EpVm por redução do radical DPPH, do NO e pela inibição da lipoperoxidação. A PA foi induzida em camundongos Swiss machos (30-35 g, n = 6 por grupo) por duas injeções sucessivas de L-arginina (4 g/kg, i.p.) e eutanasiados 72 h após a indução. Os animais foram tratados com EpVm (50, 100 e 200 mg/kg, v.o.), ou dexametasona (5 mg/kg, s.c.) ou morfina (5 mg/kg, i.p.) ou veículo (NaCl, 0,9%) a cada 24 h, iniciando-se 1 h após indução da PA. Após a eutanásia, foram avaliados parâmetros inflamatórios (atividade de mieloperoxidase e concentração de fator de necrose tumoral [TNF]-α, interleucina [IL]-1β e IL-6 nos tecidos pancreático e pulmonar, contagem de leucócitos no sangue e índice de edema no pâncreas), marcadores de estresse oxidativo (formação de substâncias reativas ao ácido tiobarbitúrico [TBARS], conteúdo de grupos sulfidrila não proteicos [NP-SH], conteúdo de radicais carbonil e capacidade total de redução do ferro [FRAP] em pâncreas e pulmão), atividade das enzimas antioxidantes (atividade de catalase [CAT], superóxido dismutase [SOD] e glutationa peroxidase [GSH-Px] no pâncreas e pulmão), parâmetros bioquímicos (amilase, lipase, alanina aminotransferase, aspartato aminotransferase, ureia e creatinina no soro) e a hiperalgesia abdominal. A indução da PA pela L-arginina alterou significativamente os parâmetros de inflamação e estresse oxidativo, bem como a hiperalgesia, em relação ao grupo veículo. O tratamento com EpVm inibiu a hiperalgesia abdominal causada pela PA. Todos os parâmetros inflamatórios foram reduzidos quando os animais foram tratados com EpVm. O tratamento com EpVm diminuiu parcialmente as alterações nos parâmetros bioquímicos no soro. A atividade de SOD e CAT no pâncreas e pulmão, que se encontravam reduzidas pela PA, foram restauradas após tratamento com EpVm, mas a atividade de GSH-Px não foi alterada. A formação de TBARS e radical carbonil foi reduzida após tratamento com EpVm e o NP-SH foi aumentado após este tratamento, assim como o FRAP no pâncreas e no pulmão. Em suma, estes resultados indicam que as PM possuem potencial para o tratamento da PA experimental e que o EpVm diminui a inflamação, o estresse oxidativo e a hiperalgesia na PA em camundongos, tornandoo de interesse em abordagens futuras para tratar esta condição.

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