Made available in DSpace on 2014-12-17T15:42:04Z (GMT). No. of bitstreams: 1 RoseliaSL.pdf: 2427942 bytes, checksum: 72c973dd87b5433d7d0b592195af336a (MD5) Previous issue date: 2008-09-02 / In this present work an ethnographic research was performed with 84 native medicinal specimens from the Litoral Norte Riograndense, from which two plants Cleome spinosa Jacq e Pavonia varians Moric were submitted to ethnobotanic, phytochemistry and pharmacologic investigations. Additionally, a phytopharmacological research of the medicinal specimen Croton cajucara Benth ( native plant of the Amazon region of Brazil) was improved. The obtained phytochemical results of the C. spinosa and P. varians showed the presence of flavonoids constituents, among other components. The two flavonoids (2S)-5-hydroxy-7,4 -dimethoxy-flavanone and 5,4 -dihydroxy-3,7,3 -trimethoxy-flavone were isolated from C. spinosa. The antioxidant activity of the hydroalcoholic extracts of C. spinosa and P. varians solubilized in the microemulsion systems SME-1 and SME-4, was evaluated in the DPPHmethod. The used SME systems [obtained with Tween 80: Span 20 (3:1) and isopropyl myristate (IPM)] improved the dissolution of those tested polar extracts, with higher efficacy to the SME-1 system (in which ethanol was included as cosurfactant). The CE50 values evidenced for P. varians were 114 [g/mL (SME-1) and 246 [g/mL (SME-4); for C. spinosa it was 224 [g/mL (SME-1) and 248 [g/mL (SME-4), being the system SME-1 more effective for both tested extracts. The hydroalcoholic extracts of P. varians (HAE-PV) was also submitted to pharmacological screening for antinociceptive activity in animal models. The oral administration of this extract (100, 300 and 1000 mg/kg) inhibited the acetic acid-induced writhing in mice. The higher inhibition (74%) was evidenced to the 1000 mg/kg administered dose. Its effect on the central nervous system (CNS) was investigated by tail flick and formalin-method and reveled that it has negligible antinociceptive action on the CNS. After taking consideration of HAE-PV interaction, Pavonia varians Moric could be used as a potent analgesic agent in case of peripheral algesia, without affecting the CNS. The phytochemical study of the stem bark of Croton cajucara Benth lead to the isolation of 19-nor-clerodanetype diterpenes, as well as to the separation of its fixed oil FO-CC. This non polar oil material reveled to be rich in sesquiterpenes and 19-nor-clerodanes components. The biologic effect of OF-CC was evaluated in the development in vitro of the fungis phytopatogens such as Fusarium oxysporum, Rhizoctonia solani and Sclerotium rolfsii. Significant inhibitory effect of the tested fungis (at 0,2 mg.mL-1 dosage) were comproved. A Mass Spectrometry study of clerodane-type diterpenes was developed in order to identify characteristic fragments on mass spectrometra of both clerodane and 19-nor-clerodane presenting an α,β-insaturated carbonyl moiety at ring A of the decalin-system. For that study, mass spectroscopy data were analysed for 19-nor-clerodanes [trans-dehydrocrotonin (DCTN), trans-crotonin (CTN), cis-cajucarin B (c-CJC-B), and cajucarinolide (CJCR)] and for clerodanes [isosacacarin (ISCR) and transcajucarin A (t-CJC-A)] obtained from the stem bark of C. cajucara, and also clerodane-type from other species. The trans-junction of the enone-system clerodanes was clear correlated with the presence of the characteristic ions at m/z 95, 121 e 205. Meanwhile, the characteristics ions at m/z 122 e 124 were correlated to cis-junction. The trans-junction of the enone-system 19-nor-clerodanes showed characteristics ions at m/z 161, 134 e 121. This study could be successful employed for identification of clerodane constituents from other specimens without any additional spectroscopic analyses, as well as a previously phytochemical analyzes in clerodane project search / Neste trabalho realizou-se uma pesquisa etnogr?fica envolvendo oitenta e quatro esp?cimes vegetais nativas do Litoral Norte Riograndense. Duas destas esp?cies Cleome spinosa Jacq e Pavonia varians Moric foram alvo de estudos etnobot?nico, fitoqu?mico e farmacol?gico. Em adi??o, ampliou-se os estudos fitofarmacol?gicos de Croton cajucara Benth, uma esp?cie medicinal nativa da regi?o Amaz?nica. Os resultados fitoqu?micos de Cleome spinosa e Pavonia varians indicaram dentre outros metab?litos especiais, a presen?a de flavon?ides. Os flavon?ides (2S)-5-hidroxi-7,4 -dimetoxi-flavanona e 5,4 -diidroxi-3,7,3 -trimetoxi-flavona foram isolados de Cleome spinosa. A atividade antioxidante dos extratos hidroalco?licos de P. varians e C. spinosa solubilizados em sistemas microemulsionados (SME), foi avaliada frente ao radical livre DPPH. Os sistemas SME-1 e SME-4 [contendo Tween 80: Span 20 (3:1) e miristato de isopropila (IPM)] mostraram-se eficazes na solubiliza??o dos extratos avaliados, tendo sido observado melhor efic?cia para o sistema SME-1 [EC50 = 113,84 μg/mL (SME-1) and 246,00 μg/mL (SME-4) para P. varians e EC50: 223,97 μg/mL (SME-1) e 248,37 μg/mL (SME-4) para C. spinosa (sistema SME-1contendo etanol como cotensoativo e SME-4, isento de cotensoativo]. A a??o antinociceptiva de Pavonia varians foi confirmada atrav?s do teste das contor??es abdominais, tendo sido observado rela??o dose/efeito inibit?rio dependente do extrato hidroalco?lico desta esp?cie. Os testes do tipo tail flick e da formalina afastaram a possibilidade da participa??o de mecanismos antinociceptivos no sistema nervoso central. No entanto, no teste da formalina evidenciou-se a participa??o de mecanismos antiinflamat?rios na produ??o do efeito antinociceptivo deste extrato. O estudo fitoqu?mico das cascas do caule de Croton cajucara Benth conduziu ao isolamento de diterpenos do tipo 19-nor-clerodano, bem como ? obten??o do ?leo fixo OF-CC, rico em sesquiterpenos e 19-nor-clerodano bioativos. O efeito de OF-CC foi avaliado no desenvolvimento in vitro dos fungos fitopatog?nicos Fusarium oxysporum, Rhizoctonia solani e Sclerotium rolfsii propagados em meio de cultura Batata-dextrose-agar. A resposta fisiol?gica, variou de acordo com o tipo de fungo testado, tendo sido observado que o OF-CC apresentou efeito fungist?tico significativo, com efeito inibit?rio mais est?vel para o g?nero de fungo Fusarium oxysporum. Realizou-se ainda, um estudo de espectrometria de massas objetivando-se a identifica??o de fragmentos caracter?sticos de diterpenos do tipo clerodano (com dados obtidos na literatura) e 19-nor-clerodano (isolados das cascas do caule de C. cajucara), tendo sido evidenciado que a jun??o trans de clerodanos est? correlacionada com a presen?a dos ?ons caracter?stico de m/z 95, 121 e 205. Os sistemas de jun??o cis de clerodanos apresentaram ?ons caracter?sticos de m/z 122 e 124. A jun??o trans de 19-nor-clerodanos foi correlacionada com a presen?a dos ?ons caracter?stico de m/z 161, 134 e 121. Este estudo pode ser utilizado na identifica??o de diterpenos do tipo clerodano e 19-nor-clerodano, contendo carbonila α,β-insaturada no anel A do sistema decal?nico, evitando desta forma, a brigatoriedade de isolamento e caracteriza??o via RMN

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Nitrogen-fixing bacteria in soybean nodules convert atmospheric nitrogen to plant-available forms in exchange for carbon from the plant, but other non-nitrogen-fixing bacteria also reside in nodules, and their role in the nodule is not well understood. This study was conducted to determine the effect of three non-nitrogen-fixing Pseudomonas spp. strains isolated from nodules on soybean, and we hypothesized these strains benefit soybean. A greenhouse study in which two cultivars of soybean (Asgrow AG46X6 and Pioneer P48A60X) were treated with three fluorescent Pseudomonas spp. strains (referred to in this study as Bullseye, Pancake, and Starfish) and an uninoculated control. Soybeans were harvested at two time points: the R2/R3 growth stage and the R6 growth stage. Following each harvest, measures of growth, yield, and nitrogen fixation were taken, and data were analyzed using two non-parametric, multivariate analyses: multiple response permutation procedure (MRPP) and permutational multivariate analysis of variance (PERMANOVA). Both analyses showed soybeans of both cultivars treated with Pancake differed from controls following the first harvest but not the second. When analyzed individually, most metrics for growth, yield, and nitrogen fixation following the first harvest were not significantly different between Pancake and control treatments, but Pancake treatment means were still generally higher than controls. If metrics are considered collectively in conjunction with the results of the multivariate analyses, the results show Pancake generally increased soybean growth and nitrogen fixation. These findings support the hypothesis that non-nitrogen-fixing bacteria from nodules benefit plants, and such bacteria have the potential to serve as biofertilizers. / Master of Science in Life Sciences / Soybeans are one of the most commonly grown crops in the world, and nitrogen-fixing bacteria colonize the roots of soybeans and initiate the formation of spherical nodules attached to the roots. Inside the nodules, these bacteria convert atmospheric nitrogen to plant-available forms in exchange for sugar from the plant, and such bacteria reduce the need to add nitrogen fertilizer to agricultural fields. Other non-nitrogen-fixing bacteria also reside in nodules, but their role in the nodule is not well understood. If these bacteria benefit soybeans, they have the potential to serve as biofertilizers (microbial inoculants that promote plant growth). This study was conducted to determine whether non-nitrogen-fixing bacteria isolated from nodules benefit soybean. A greenhouse study in which two cultivars of soybean (Asgrow AG46X6 and Pioneer P48A60X) were grown in soil and were either left uninoculated or were inoculated with one of three strains of bacteria from the genus, Pseudomonas (referred to in this study as Bullseye, Pancake, and Starfish). Following harvest, measures of growth, yield, and nitrogen fixation were taken, and data showed the bacteria generally benefited the soybean plants. Although, these results showed the bacteria benefitted the plants, field trials and further testing in the greenhouse should be conducted before using these bacteria as commercial biofertilizers. Additionally, the effects of other non-nitrogen-fixing nodule bacteria on soybeans should also be tested to identify other beneficial strains, and the cost of production should be compared to the potential gains of using such bacteria before they are developed into biofertilizers.

Poor loan repayment causes the decline and failure of some microfinance institutions. The purpose of this qualitative multiple case study was to explore strategies that microfinance (MFI) leaders use to reduce loan default in the base of the pyramid market. The study population included 6 MFI leaders, 12 borrower community-based groups, and 4 staff members of the Adventist Development and Relief Agency (ADRA Rwanda) who reduced MFI loan default in Rwanda. Data were collected through semistructured interviews with 3 MFI leaders, 3 ADRA Rwanda staff members, and 3 members of borrower groups. Data were also collected through focus groups with 3 borrower community-based groups comprising 6 to 8 members. Additional data were collected through the analysis of MFI and ADRA Rwanda organizational documents. The Varian group lending model was the conceptual framework for the study. Data analysis involved methodological triangulation and the Gadamerian hermeneutics framework of interpretation. Four major themes emerged: intrapreneurship and environmental business opportunities, favorable loan repayment conditions, strategies for choosing borrower groups, and loan use monitoring. A sustainable microfinance institution can produce social change by providing microfinance loans that clients can use to start and grow microenterprises that can become the source of income for improving the lives of clients and their family members. Findings may also be used to create economic growth through the participation of more people in economic activities in the base of the pyramid market.