Les invasions biologiques font partie des changements globaux qui contribuent à la perte de biodiversité. Les plantes invasives peuvent aussi provoquer des pertes économiques, notamment d'importants coûts pour leur contrôle. Dans l'archipel des Mascareignes plusieurs programmes de gestion ont été mis en place pour contrôler les espèces invasives. La perception du public sur les espèces invasives varie fortement entre les parties prenantes. En raison d'opinions divergentes sur la gestion des invasions, les travaux de recherche et de mise en œuvre de programme de lutte ont récemment généré des conflits d'usage. Ce travail de thèse a permis de conduire une étude pluridisciplinaire sur les dimensions socio-écologiques et économiques de la gestion de Rubus alceifolius, objet d'un programme de contrôle biologique à l'île de La Réunion. Nous avons mené une analyse économique des différentes options de gestion de R. alceifolius et des coûts futurs de son invasion. Nous avons évalué l'impact de la lutte biologique sur le rétablissement des espèces indigènes dans une aire protégée. Le succès économique et écologique du programme de contrôle biologique de R. alceifolius a été démontré dans les habitats d'altitude < 800 m. Afin de comprendre la raison des conflits entre les parties prenantes nous avons parallèlement développé un travail de recherche socio-anthropologique. Nous avons pu mettre en évidence des faiblesses dans le processus de prise de décision et de mise en œuvre collective de ce programme de lutte. Ces travaux de thèse mettent en exergue le besoin crucial d'identifier et d'impliquer les parties prenantes à toutes les étapes du programme de contrôle biologique. / Biological invasions contribute to the degradation of biodiversity globally. Invasive alien plants have impacted on natural resources management and have generated substantial costs of control and economic loss. Various management options have been put in place to control the level of invasions of targeted species. The public’s perception of invasive species varies among stakeholders. Controversies and conflicts emerged as a consequence of diverging opinions on the management of invasions. We conducted an inter-disciplinary study on the socio-ecological and economic dimensions related to the management of the invasive Rubus alceifolius, following a biological control programme in Réunion Island (France). Firstly, we carried out an economic analysis of the management options for R. alceifolius with future scenario on the cost of invasion. Secondly we assessed the impact of the recovery of native species post biological control. Thirdly a socio-anthropological investigation to understand the rationale behind controversies amongst stakeholders, was investigated. Lastly, a gap-analysis of the policy framework corresponding to a biological control programme was conducted. We found that the biological control programme of R. alceifolius was successful within the elevation limit of 800 m, from both an economic and ecological perspective. Given the shortfall in the decision-making process and implementation, this study demonstrated the crucial need to identify and involve stakeholders in all stages of a biological control programme. We concluded with key recommendations for successful biological programmes.

Os produtos cosméticos e farmacêuticos contendo componentes de origem natural têm aumentado significativamente nos últimos anos. Com o objetivo de utilizar esses componentes como conservante em formulações cosméticas, determinou-se a atividade antimicrobiana do extrato bruto de folhas de Rubus rosaefolius Sm. e suas frações. Aquele de melhor desempenho foi avaliado quanto à toxicidade in vitro e seu comportamento em formulações cosméticas (creme, gel e xampu), relacionado à estabilidade, eficácia do sistema conservante e compatibilidade epidérmica. A atividade antimicrobiana foi determinada pelo método de microdiluição e a concentração de 0,2% (p/v) do extrato bruto apresentou melhor desempenho. O teste de toxicidade do extrato bruto foi realizado por meio do método colorimétrico Cell Titer 96®, MTS, em cultura de queratinócitos humanos, constatando-se índice de citotoxicidade (IC50) de 1,0 mg/mL. As formulações cosméticas contendo o extrato foram analisadas quanto à estabilidade e as de melhor desempenho foram submetidas ao teste de eficácia do sistema conservante, de acordo com os procedimentos descritos na CTFA. O sistema conservante mostrou-se efetivo frente à Escherichia coli IAL 2393 (ATCC 10536), a Pseudomonas aeruginosa IAL 1874 (ATCC 9027), ao Staphylococcus aureus IAL 1875 (ATCC 6548), a Burkholderia cepacia IAL 1834 ATCC (17759) e a Candida albicans IAL 1611 (ATCC 10231). Avaliouse a compatibilidade epidérmica das formulações em equivalentes dermo-epidérmicos, sistema tridimensional cultivados na superfície ar-líquido. Os resultados mostraram que houve diferenças na compatibilidade epidérmica dependendo das características dos componentes das formulações. Concluiu-se que o extrato bruto de folhas de Rubus rosaefolius Sm. a 0,2% (p/v) pode ser utilizado como candidato a conservante em formulações cosméticas, sendo estável e apresentar compatibilidade epidérmica. / Cosmetic and pharmaceuticals products contained natural compounds have increased in the last few years. To verify the use of these compounds as preservative in formulations, the antimicrobial activity from the raw extract of the Rubus rosaefolius Sm. leaves and its fractions was determined. The toxicity in vitro and the behavior in cosmetic formulations (gel, emulsion and shampoo), regarding to the stability, effectiveness of the preservative system, and epidermal compatibility were evaluated in the extract, which had the best preservative action. The antimicrobial activity was determined by the micro dilution method, and the 0.2% concentration (w/v) of the raw extract had the best performance. The toxicity of the extract was analyzed by Cell Titer 96® colorimetric; MTS method in human keratinocytes culture, and the index of cytotoxicity (IC 50) found was 1.0 mg/mL. The cosmetic formulations with the raw extract were analyzed regarding to the stability and the best formulations were submitted to preservative challenge test, according to CTFA procedures. The preservative system was effective against Escherichia coli IAL 2393 (ATCC 10536), Pseudomonas aeruginosa IAL 1874 (ATCC 9027), Staphylococcus aureus IAL 1875 (ATCC 6548), Burkholderia cepacia IAL 1834 ATCC (17759), and Candida albicans IAL 1611 (ATCC 10231). The epidermal compatibility of the formulations was verified by skin (dermo-epidermal) equivalent, three-dimensional system, cultivated in the air-liquid surface. The results showed there were differences in the epidermal compatibility depended on the ingredient of formulation. In conclusion, the raw extract from the Rubus rosaefolius Sm leaves 0.2% (w/v) can be used as preservative candidate in the cosmetic formulations analyzed due to stability and it presented epidermal compatibility.

Made available in DSpace on 2014-08-20T14:22:03Z (GMT). No. of bitstreams: 1 dissertacao_leticia_vanni_ferreira.pdf: 2636799 bytes, checksum: 2bcdbd5cd409544bc1b70a9c46aede8f (MD5) Previous issue date: 2012-03-16 / The blackberry is a rustic specie and despite it has been introduced in Brazil in the 1970, there is few works about the cultural practices of this rosacea were conducted. The aim of this work was to evaluate production and quality of blackberries, using different trellis systems, castor bean pie as fertilization and calcium foliar applications in preharvest. The experiments were conducted at Embrapa Temperate Climate, Pelotas-RS and the chemical analyses, were made at Postharvest Fisiology Laboratory of this institution, from 2010 to 2012. In the first experiment was evaluation the trellis systems type, spaced between row of 0.50 x 3.0m, where the experimental design was in randomized block, with a factorial design 3x3: being three conduction systems (free, trelli and Y ) and three cultivars of blackberry (Tupy, Guarani and Xavante). The cultivar Tupy showed a higher production and fruit flesh average in all conduction systems. The system Y showed better results. In the second experiment was castor bean pie applicated as a base fertilization. The cultivar was cultivar Tupy, using the row spacing as 0.70 x 3m. The treatments were: T1- pattern; T2- 200; T3- 400; T4- 800; T5- 1.600 grams of castor bean pie per plant. The experimental design was randomized blocks. The variables haven t been influenced by castor bean pie. In the third experiment was the calcium foliar application in preharvest. The experimental design was randomized. In 2010 the experiment had four repetitions with eight fruits per repetition, with a factorial design 2x5x2, with two fertilizations levels with and without castor bean pie; five calcium foliar applications x g L-1 (0, 1, 2, 3 and 4 applications), and two storage periods on cold chamber (0 and 3 days). In 2011, there were three repetitions with ten fruits per block, and were doubled the application number of calcium foliar (0, 2, 4 and 8), and it was kept the same concentration per application, and three storage times (0, 3 and 8 days), with a factorial design 2x4x3. During storage there was a reduction of SS of blackberries, and there were significant losses of blackberries mass. The treatment which received a larger number of calcium applications showed a smaller mass loss of fruit. The calcium applications didn t influence the fruit firmness. / A amoreira-preta é uma espécie rústica e, apesar de ter sido introduzida no Brasil na década de 70, poucos trabalhos de manejo desta rosácea foram realizados. Objetivou-se com o presente trabalho avaliar a produção e qualidade de amoreiras-pretas, utilizando diferentes sistemas de condução, doses de torta de mamona como adubação e aplicações de cálcio em pré-colheita, visando a manutenção da fruta em pós-colheita. Os experimentos foram realizados na Embrapa Clima Temperado, Pelotas/RS e, as análises químicas, no Laboratório de Fisiologia da Pós-colheita da mesma, no período 2010 a 2012. No experimento 1, avaliou-se os sistemas de condução, o espaçamento utilizado foi de 0,50 x 3,0m, o delineamento experimental foi em blocos casualizados, em um fatorial 3x3: três sistemas de condução (sem tutor, espaldeira e Y ) e três cultivares de amoreira-preta (Tupy, Guarani e Xavante). A cultivar Tupy apresentou maior produção e massa média de fruta em todos os sistemas de condução. O sistema em Y possibilitou melhores resultados. No experimento 2, testou-se a aplicação de torta de mamona como adubação de base, utilizou-se a cultivar Tupy, com espaçamento de 0,70 x 3m. Os tratamentos foram: T1- testemunha; T2- 200; T3- 400; T4- 800; T5- 1.600 gramas de torta de mamona por planta. O delineamento experimental foi o de blocos ao acaso. As variáveis não foram influenciadas pelas doses de torta de mamona. No experimento 3, avaliou-se a aplicação de cálcio em pré-colheita, o delineamento experimental foi inteiramente casualizado. Em 2010 o experimento teve quatro repetições de oito frutas por repetição, num esquema fatorial 2x5x2, duas adubações com e sem torta de mamona; cinco de aplicações de cálcio (0, 1, 2, 3 e 4 aplicações), e dois períodos de armazenamento em câmara fria (0 e 3 dias). Em 2011, utilizou-se três repetições de dez frutas por parcela, e duplicou-se o número de aplicações de cálcio (0, 2, 4 e 8), matendo-se a mesma concentração por aplicação, e três períodos de armazenamento (0, 3 e 8 dias), num esquema fatorial 2x4x3. Durante o armazenamento ocorreu redução dos sólidos solúveis totais das amoras-pretas. Com o armazenamento ocorreram perdas significativas de massa das amoras-pretas. O tratamento que recebeu maior número de aplicações de cálcio apresentou menor perda de massa das frutas. As aplicações de cálcio não influenciaram na firmeza da fruta.

Avec l'augmentation des sécheresses dans les forêts tempérées, la gestion sylvicole envisage de réduire la densité des peuplements adultes pour limiter le déficit hydrique. Cependant, la réduction de la canopée arborée augmente le rayonnement dans le sous-bois et permet le développement de la strate herbacée monopoliste. Nos objectifs étaient de caractériser l'évapotranspiration (ETu) de 4 herbacées monopolistes (Molinia caerulea, Calluna vulgaris, Pteridium aquilinum and Rubus sp.) et de quantifier leur impact sur la teneur en eau du sol (SWC) dans des peuplements de Quercus petraea. L’ETu des quatre herbacées cultivées en pot a été quantifiée en conditions semi-contrôlées caractérisées par deux niveaux d’éclairement relatif et 3 niveaux de SWC. In situ, le SWC, le microclimat et l’ETu de P. aquilinum et M. caerulea ont été mesurés sur 20 dispositifs dans les peuplements forestiers de Q. petraea présentant un gradient croissant de LAI. Chaque dispositif était subdivisé en 2 placettes, l’une était désherbée et l'autre enherbée. M. caerulea et C. vulgaris ont une faible régulation de leur ETu alors que P. aquilinum et Rubus sp. ont une stratégie conservatrice face au stress hydrique. SWC diminue plus rapidement quand le LAI de la strate herbacée augmente, ce qui est directement lié à l’ouverture du couvert arboré avec une valeur seuil de LAI de la strate arborée à 2-3, sous laquelle la contribution de la strate herbacée à l’évapotranspiration du peuplement pourrait compenser la diminution de celle de la strate arborée.Ces résultats montrent la nécessité de considérer la végétation du sous-bois dans la gestion sylvicole notamment lorsque la ressource hydrique est limitante. Ainsi, la réduction de la densité de la strate arborée doit être un compromis entre la réduction de la surface foliaire des arbres pour réduire l’ET, et le maintien d’une densité suffisante de la strate arborée pour limiter la croissance et l'ETu de la végétation du sous-bois. / In the context of ongoing increase of drought in temperate forests, forest managers consider the reduction of stand density to limit soil water depletion. The reduction of tree canopy density increases light below canopy and allows the development of monopolistic understorey vegetation. Our objectives were to characterize the evapotranspiration (ETu) of common understorey plants (Molinia caerulea, Calluna vulgaris, Pteridium aquilinum and Rubus sp.) and to quantify their impacts on soil water content (SWC) in mature oak stands (Quercus petraea).A first experiment was set up in a greenhouse where the 4 understorey species were potted and subjected to 2 levels of light transmittance and 3 levels of SWC. Microclimate and ETu were monitored. A second experiment was carried out on 20 plots (10 with M. caerulea and 10 with P. aquilinum) in oak stands with contrasted LAI. On each plot, two circular areas were set up, one weeded and the other untouched. SWC, microclimate and ETu were monitored.M. caerulea and C. vulgaris are more water spenders, whereas P. aquilinum and Rubus sp. are more water savers under water stress. Soil water depletion was faster with increasing understorey vegetation LAI, which was directly linked to tree canopy opening with a threshold of tree LAI of 2-3 below which the understorey contribution could offset the reduction of tree ET. The experimentations showed that the relative contribution of understory vegetation in the ecosystem water balance is significant, and depends on SWC and on the understorey species identity. These results show the necessity to consider understorey vegetation in forest management when water availability is an issue. Lower tree canopy density could increase the understorey ETu and soil water stress for trees. From a management perspective, thinning should be designed as a compromise between the reduction of tree leaf area to reduce ET, and maintaining sufficient tree canopy to restrict the growth and ETu of understorey vegetation.

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Our planet is in the midst of a biodiversity crisis, with factors such as land transformation, climate change, anthropomorphic disturbance and invasive species acting together to threaten biodiversity. In South Africa, with minimal natural wood resources, commercial forestry is one of the most abundant forms of landscape transformation. However, a third of the land inside many plantations has been set aside for conservation as unplanted remnant grassland patches (RGPs). These areas are subjected to an additional negative impact by invasive alien species, namely Rubus cuneifolius (American bramble), a weed that is particularly problematic in and around forestry plantations in South Africa. The grassland biome of South Africa is extremely diverse and is of vital importance for the ecosystem services it supplies. Despite this, the grassland biome is under threat as this is where much of South Africa’s forestry plantations are located. Driven by anthropomorphic disturbance, pollinators are in decline. Landscape transformation of natural areas for forestry plantations is likely to affect plant-pollinator interactions which will affect ecosystems and biodiversity. However, it is not known to what extent these ecosystems are affected. It is thought that the impact depends on the complexity of the ecosystem in question, and analyses at the network-level provide insights into the robustness of ecosystems in the face of biodiversity loss. Thus, this study evaluates the effect of natural habitat fragmentation and invasion of the alien species, R. cuneifolius, on flower visitation networks of South African grasslands. The study was conducted in the KwaZulu-Natal Midlands within a commercial timber plantation and a neighbouring protected area (PA). Flower-visitor observations were carried out in uninvaded protected areas and RGPs and in protected areas and RGPs invaded by R. cuneifolius. I found that RGPs within commercial forestry plantations successfully decrease the negative effects of land transformation on the grasslands of the KwaZulu-Natal Midlands, and flower visitation network patterns are largely maintained in these habitat fragments. However, within RGPs, invasion by R. cuneifolius affected the composition and the interaction network structure of flower-visitor and plant communities. The fact that there are unplanted areas within commercial forestry plantations is positive for biodiversity conservation in South Africa. Research has indicated that these areas successfully aid in the conservation of biodiversity and ecosystem functioning. Due to the positive influence that RGPs have on conservation in fragmented and transformed landscapes, it is critical that these unplanted areas are retained. However, the effects of bramble invasion are more intense within RGPs than within protected areas, and therefore, it must be a priority to keep these areas undisturbed. R. cuneifolius has been found to have devastating effects on ecosystem function and network structure. It is also a category 1 invasive plant within South Africa, and its removal is required by law. Therefore, the removal of bramble must be a management priority. / AFRIKAANSE OPSOMMING: Ons planeet is in die middel van 'n biodiversiteit krisis, met faktore soos grond transformasie, klimaatsverandering, antropomorfiese versteuring en indringerspesies wat gesamentlik werk om biodiversiteit te bedreig. Suid-Afrika, besit minimale houtbronne. Daarom is kommersiële bosbou een van die mees algemene vorme van landskap transformasie. Tog is 'n derde van die land binne baie plantasies opsy gesit vir bewaring as oorblywende grasveld kolle (OGKs). Hierdie gebiede word ongelukkig blootgestel aan die bykomende negatiewe impak van die uitheemse spesies, Rubus cuneifolius (Amerikaanse steekdoring), wat veral problematies is in en rondom bosbouplantasies. Die grasveldbioom van Suid-Afrika is baie divers en is van kardinale belang vir die ekosisteem dienste wat dit lewer. Ten spyte hiervan, word die grasveldbioom bedreig waar dit op dieselfde areas as die meerderheid van Suid-Afrika se bosbouplantasies geleë is. Antropomorfiese versteuring lui daartoe dat bestuiwergetalle daal. Landskap transformasie vir bosbou plantasies raak dus plant-bestuiwer interaksies, wat ekosisteme en biodiversiteit beïnvloed. Dit is nie bekend tot watter mate hierdie ekosisteme geraak word nie. Daar word vermoed dat die impak af hang van die kompleksiteit van die ekosisteem. Ontledings van ekosisteme op netwerk vlak kan insigte bied oor die robuustheid van hierdie ekosisteme in die aangesig van biodiversiteitverlies. Dus, die studie evalueer die effek van fragmentasie van natuurlike habitatte en inval van die indringer spesie, R. cuneifolius, op blom-besoekings netwerke van Suid-Afrikaanse grasvelde. Hierdie studie is uitgevoer in die KwaZulu-Natal Midlands binne 'n kommersiële hout plantasie en 'n naburige beskermde gebied (BG). Blom-besoeker waarnemings was in BGs en OGKs sonder R. cuneifolius, en in BGs en OGKs met R. cuneifolius uitgevoer. Ek het gevind dat OGKs binne kommersiële bosbouplantasies suksesvol is om die negatiewe uitwerking van land transformasie te verminder, en blom-besoeking netwerk patrone grootliks gehandhaaf word in hierdie habitat fragmente. Egter, binne OGKs, het R. cuneifolius die samestelling en die interaksie netwerk struktuur van blom-besoekers en plant gemeenskappe negatief geraak. Die feit dat OGKs ongeplant gelaat word, is positief vir die bewaring van biodiversiteit in Suid- Afrika. Navorsing dui aan dat hierdie gebiede suksesvol is om te help met die bewaring van biodiversiteit en ekosisteemfunksionering. As gevolg van die positiewe invloed van OGKs op bewaring in gefragmenteerde en omskepte landskappe, is dit krities dat hierdie areas ongeplant bly. Egter, die gevolge van steekdoring inval is meer intens binne OGKs as binne beskermde gebiede, en daarom moet dit 'n prioriteit wees om hierdie gebiede ongestoord te hou. R. cuneifolius se verwoestende uitwerking op ekosisteem funksie en netwerk struktuur was baie duidelik. Dit is ook 'n kategorie 1 indringerplant in Suid-Afrika, en sy verwydering word deur is die wet vereis. Daarom moet die verwydering van steekdoring ‘n bestuursprioriteit wees.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.

There exists an increasing demand for computing power and performance in real-time embedded systems, as new, more complex customer requirements and function-alities are appearing every day. In order to support these requirements and func-tionalities without breaking the power consumption wall, many embedded systems areswitching from traditional single-core hardware architectures to multi-core architec-tures. Multi-core architectures allow for parallel execution of tasks on the multiplecores. This introduces many benets from the perspective of achievable performance,but in turn introduces major issues when it comes to the timing predictability ofthe real-time embedded system applications deployed on them. The problem arisesfrom unpredictable and potentially unbounded inter-core interferences, which occuras a result of contention for the shared resources, such as the shared system busor shared system memory. This thesis studies the possible application of constraintprogramming as a resource optimization technique for the purpose of creating oineschedules for tasks in real-time embedded system applications executing on a dual-core architecture. The main focus is placed on tightening inter-core data-propagationinterferences, which can result in lower over-all data-propagation delays. A proto-type of an optimization engine, employing constraint programming techniques on ap-plications comprised of tasks structured according to the Phased Execution Model isdeveloped. The prototype is evaluated through several experiments on a large numberof industry inspired intellectual-property free benchmarks. Alongside the experimentsa case study is conducted on an example engine-control application and the resultingschedule is compared to a schedule generated by the Rubus-ICE industrial tool suite.The obtained results show that the proposed method is applicable to a potentially widerange of abstract systems with dierent requirements. The limitations of the methodare also discussed and potential future work is debated based on these results. / <p>Presentation was held over Zoom, due to the COVID-19 situation.</p>

Objetivo: Evaluar el efecto antibacteriano y citotóxico in vitro de los extractos metanólicos de Rubus idaeus (Frambuesa), Vaccinium myrtillus (Arándano azul) y Fragaria ananassa (Fresa) sobre cepas de Streptococcus mutans (ATCC®25175) y Streptococcus sanguinis (ATCC®10556).  Métodos: Se preparó un extracto metanólico por cada fruto. Se realizaron 10 repeticiones para cada grupo de extracto en cada caso. Se utilizó Clorhexidina al 2% como control positivo. Las propiedades antibacterianas de cada extracto se determinaron mediante el método de difusión en pozo. La concentración mínima inhibitoria (CMI) fue determinada mediante el método de microdilución y la citotoxicidad se analizó mediante la prueba de reducción de MTT, utilizando una línea celular MDCK.  Resultados: El extracto metanólico de arándano azul (Vaccinium myrtillus) tuvo el mayor efecto antibacteriano con un resultado de 30.44 ± 5.72 mm frente a Streptococcus mutans y de 29.33 ± 6.13 mm frente a Streptococcus sanguinis. Los extractos metanólicos de frambuesa, arándano azul y fresa obtuvieron una concentración mínima inhibitoria (CMI) frente a Streptococcus mutans de 0.8 µg/ml, 1.6 µg/ml y 3.1 µg/ml respectivamente; y los extractos metanólicos de arándano azul y fresa frente a Streptococcus sanguinis obtuvieron 3.1 µg/ml y 12.5 µg/ml respectivamente. Los ensayos de viabilidad celular demostraron una baja citotoxicidad de los extractos a altas concentraciones. La viabilidad celular fue más alta para los extractos de Arándano azul y Fresa con 98.2%.  Conclusiones: Los hallazgos evidencian las propiedades antibacterianas de los extractos metanólicos de Rubus idaeus (Frambuesa), Vaccinium myrtillus (Arándano azul) y Fragaria ananassa (Fresa) frente a los microorganismos previamente mencionados. No se evidenció citotoxicidad de los extractos a altas concentraciones. / Objective: Evaluate the in vitro antibacterial and cytotoxic effect of Rubus idaeus (Raspberry), Vaccinium myrtillus (Blueberry) and Fragaria ananassa (Strawberry) methanolic extracts against Streptococcus mutans (ATCC®25175) and Streptococcus sanguinis (ATCC®10556) strains. Methods: A methanolic extract was prepared for each fruit. Ten independent samples were made for each group of extract. 2% Chlorhexidine was used as a positive control. Antibacterial activity of each methanolic extract was determined by the well diffusion method. The minimum inhibitory concentration (MIC) was established by the microdilution method. Cytotoxicity was analyzed by the MTT reduction test, using a MDCK cell line. Results: The methanolic extract of blueberry (Vaccinium myrtillus) had the highest antibacterial effect with a result of 30.44 ± 5.72 mm against Streptococcus mutans and 29.33 ± 6.13 mm against Streptococcus sanguinis. The methanolic extracts of raspberry, blueberry and strawberry obtained a minimum inhibitory concentration (MIC) against Streptococcus mutans of 0.8 µg/ml, 1.6 µg/ml and 3.1 µg/ml respectively; and the methanolic extracts of blueberry and strawberry against Streptococcus sanguinis obtained 3.1 µg/ml and 12.5 µg/ml respectively. Cell viability assays demonstrated low cytotoxicity of the methanolic extracts at very high concentrations. Cell viability for blueberry and strawberry methanolic extracts was the highest with 98.2%. Conclusions: The findings evidence the antibacterial properties of methanolic extracts of Rubus idaeus (Raspberry), Vaccinium myrtillus (Blueberry) and Fragaria ananassa (Strawberry) against the previously mentioned microorganisms. The methanolic extracts didn’t show cytotoxicity at high concentrations. / Tesis

No description available.

As plantas, assim como outros organismos, possuem a capacidade de se defenderem contra ataque de patógenos. Uma das respostas desencadeadas pelo reconhecimento do patógeno pelas células vegetais é a reação de hipersensibilidade (RH), que envolve a morte imediata das células do sítio primário de infecção, oferecendo resistência ao crescimento do patógeno. Muitas evidências sugerem a participação da mitocôndria neste processo de morte celular programa. O nim (Azadirachta indica) é conhecido devido as suas propriedades medicinais e inseticidas, sendo que os estudos sobre a ação inseticida dessa planta restringem-se a análise de seus mecanismos de ação sobre insetos e também de seus efeitos sobre trabalhadores rurais que fazem uso de produtos a base de nim. Entretanto não há na literatura pesquisada, trabalhos de seus impactos sobre o sistema vegetal. A partir dos resultados previamente obtidos em nosso laboratório e com as análises dos dados da literatura, consideramos de grande importância dar continuidade a esse estudo do efeito do nim como elicitor, avaliando quais mecanismos que levam ao fenômeno de resistência vegetal. O extrato de nim (EB) foi preparado a partir das sementes, sendo caracterizado bioquimicamente pela quantificação de compostos fenólicos, açúcares e proteínas. A atividade antioxidante foi avaliada sendo possível observar que o extrato das sementes de nim possui forte atividade antioxidante de maneira dose-dependente com IC50 de 14,85 mg/mL. Para os ensaios biológicos foi utilizado EB nas concentrações de 0,1 a 5 mg/mL isolado ou em associação com AS a 1 µmol/L ou 1 mmol/L. Para determinação da morte celular foi observado o efeito do EB nas concentrações de 5 e 0,1 mg/mL isolado ou em associação com AS 1 µmol/L nos tempos de 0 a 8 horas. Diante dos resultados foi observado que o EB na concentração de 0,1 mg/mL isolado ou em associação com AS 1 µmol/L foi capaz de causar morte celular em células de Rubus fruticosus de forma mais significativa do que o EB isolado ou em associação com AS na concentração de 5 mg/mL. No tempo de 8 horas, foi observado uma porcentagem de morte celular de 64 % para células elicitadas com EB 0,1 mg/mL isolado e 71 % para células elicitadas com EB 0,1 mg/mL em associação com AS. A diminuição da produção de EROs e da produção de AS endógeno bem como o aumento da produção de compostos fenólicos foi observado em células intactas elicitadas com EB isolado. No entanto quando a células foram elicitadas com EB em associação com AS observamos uma diminuição da produção de compostos fenólicos com o aumento da produção de AS endógeno. Em mitocôndrias isoladas foi avaliado o consumo de oxigênio, o potencial de membrana e a produção de EROs com o EB isolado e sua associação com AS 1 mmol/L. Foi observado que o EB isolado ou em associação com AS foi capaz de diminuir a velocidade de consumo de oxigênio pela cadeia respiratória sendo este efeito mais acentuado quando o nim foi administrado juntamente com AS, onde a porcentagem de inibição da velocidade de consumo de oxigênio pela cadeia respiratória na presença de EB em associação com AS foi de 79 % no estado 3 da respiração e 62 % no estado 4. Sobre o potencial de membrana observamos que o EB isolado ou em associação com AS foi capaz de diminuir o potencial de membrana, porém de forma pouco significativa. Para a produção de EROs observamos que o EB isolado foi capaz de diminuir a produção de EROs em mitocôndrias isoladas em cerca de 55 a 20 % na presença de antimicina A e 39 a 10 % na presença de rotenona, porém quando o EB foi administrado juntamente com AS observamos uma diminuição da produção de EROs somente para o EB nas concentrações de 0,5; 1 e 5 mg/mL. Com os resultados apresentados neste trabalho e os resultados obtidos anteriormente em nosso laboratório é possível sugerir que o extrato das sementes de nim possui um efeito protetor sobre células de Rubus fruticosus. / Plants, like other organisms, have the capacity to defend themselves against attack by pathogens. One of the responses triggered by pathogen recognition by plant cells is the hypersensitive response (HR), which involves the immediate death of cells in the primary site of infection, providing resistance to the pathogen growth. In this regard, it has been well established that mitochondria are involved in cell death. The neem tree (Azadirachta indica) is known due to its medicinal and insecticidal properties; studies on the insecticidal action of this plant had been restricted to the analysis of their action mechanisms on insects and their effects on rural workers who use neem-based products. However, its impact on plant systems has not been addressed. Considering previous results from our laboratory and literature data we assessed the effects of neem as elicitor, particularly the mechanisms leading to the phenomenon of plant resistance. The neem extract (EB) was prepared from the seeds, characterized biochemically by quantification of phenolic compounds, sugars and proteins. The extract showed strong dose-dependent antioxidant activity (IC50 of 14.85 mg/mL). EB concentrations of 0.1-5 mg/mL, alone or in association with 1 mol/L or 1 mmol/L SA (salicylic acid), were used for the biological assays. For cell death assays, EB was employed in concentrations of 0.1 and 5.0 mg/mL, alone or in association with 1 mol/L SA, during 0-8 hours. EB (0.1 mg/mL), alone or in association with 1 mol/L SA, induced Rubus fruticosus cell death more efficiently than EB alone or in association with 5 mg/mL SA. After 8 hours, a 64% of death of cells elicited with 0.1 mg/mL EB and 71% of death of cells elicited with 0.1 mg/mL EB in association with SA, was observed. Decrease in ROS generation and production of endogenous SA, as well as increased production of phenolic compounds, was observed in intact cells elicited with EB alone. However, when cells were elicited with EB in association with SA, a decreased production of phenolic compounds and an increased production of endogenous SA, was observed. In isolated mitochondria, it was measured oxygen consumption, membrane potential and ROS production for EB alone or in association with 1 mmol/L SA. In either conditions, EB decreased oxygen consumption by the respiratory chain, an effect more pronounced in association with SA: ~79 % inhibition for state 3 and ~ 62 % for state 4 respiration. Also, either neem alone or in association with SA decreased mitochondrial membrane potential, as well as ROS generation to an extent of 55-20% in the presence of antimycin A and 39-10% in the presence of rotenone; in association with SA, EB decreased ROS at 5, 1 and 0.5 mg/mL. Together with our previous study, these results suggest that neem seeds extract has a protective effect on Rubus fruticosus cells by scavenging, via phenolic compounds, reactive oxygen species generated by SA, thereby decreasing its action as cell death inducer.