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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.
41

Paracoccidioides lutzii: estudo de alguns mecanismos de patogenicidade / Paracoccidioides lutzii: study of some mechanisms of pathogenicity

Martha Eugenia Uran Jimenez 23 April 2015 (has links)
A paracoccidioidomicose (PCM) é uma doença granulomatosa sistêmica, causada por Paracoccidioides spp., (P. brasiliensis e P. lutzii), geograficamente, limita-se a América Latina com as áreas endêmicas estendendo-se desde o México até a Argentina, constituindo uma das micoses sistêmicas de maior incidência na região, afetando principalmente trabalhadores rurais. O maior número de pacientes com PCM tem sido reportado principalmente no Brasil, Colômbia e Venezuela. A incidência real desta micose encontra-se subestimada no Brasil e pouco se conhece em relação a nova espécie descrita - P. lutzii. A maioria dos estudos em P. lutzii foram focados em genética, especiação e na geração de novos antígenos para melhorar a especificidade e sensibilidade dos testes sorológicos. Atualmente, as preparações antigênicas tradicionais, preparadas a partir de isolados de P. brasiliensis, são ineficientes. Raros são os trabalhos focados na biologia de P. lutzii e nos fatores de virulência que podem ser comparados com P. brasiliensis nos modelos experimentais. A nossa proposta de estudo foi avaliar alguns aspectos in vitro e in vivo relacionados com a patogenicidade e destacamos: a fagocitose e a morte intracelular de P. lutzii por macrófagos, peritoneais, de camundongos Knockouts (KO) e selvagens para PRRs (TLR2, TLR4 e Dectina) e ativadores intracelulares (MyD88 e NALP3). Paralelamente a este estudo, animais foram infectados com leveduras de P. lutzii e comparados com os modelos de infecção já estabelecidos com leveduras (Pb18) e conídios (ATCCPb60855) de P. brasiliensis. Nossos dados indicam que similar ao que ocorre com P. brasiliensis a fagocitose de P. lutzii depende de TLR2, TLR4 e Dectina- 1, resultados semelhantes também foram observadas na expressão de moléculas envolvidas na co-estimulação e a apresentação de antígenos (MHC II, CD80 e CD86). Contudo, a morte intracelular de leveduras de P. lutzii é claramente dependente de TLR4, e a produção de citocinas IL-6, MIP-2, IFN- e IL-12p40 são importantes para o controle das leveduras pelos macrófagos. No modelo experimental de P. lutzii, camundongos machos C57BL/6 (6-7 semanas) foram infectados intratraquealmente como 1x106 leveduras viáveis do isolado de P. lutzii Pb01. Encontramos duas fases da doença, a primeira de 0 hora até 2 a 4 semanas pós-infecção, e a segunda de 4 até 12 semanas. As leveduras parecem ser contidas na primeira semana de infecção e posteriormente não encontramos leveduras nos macerados de pulmão, diferente do modelo de BALB/c infetado com conídios de ATCC-Pb60855 no qual as UFC são recuperadas até a semana 16 pós-infeção. Como relação aos níveis de citocinas, encontramos que na lavagem broncoalveolar e macerado de pulmão um perfil misto Th1/Th2 porém, marcado por citocinas próinflamatórias no primeiro período e citocinas regulatórias tipo Th2 no segundo período (IL-12p70, IL-23, IL-10); similar ao descrito nos modelos de P. brasiliensis infectados tanto com conídios como com leveduras. No entanto, no primeiro período da doença, em camundongos C57BL/6, parece ter uma carga inflamatória maior que reflete nas citocinas que mantém seus níveis até o período crônico: TNF-alfa, MIP-2 e GM-CSF está última, regulada positivamente tanto em experimentos in vitro como in vivo. Também observamos que a partir das 48horas pós-infecção encontramos níveis aumentados de IL-12p70 até o período crônico onde junto com a IL-23 parecem ser as responsáveis pela diminuição da infecção no período tárdio. Esta é a primeira vez que se descreve um modelo experimental com P. lutzii (isolado Pb01) indicando o perfil imunopatológico com pequenas diferenças comparados ao P. brasiliensis porém, de importância na patogenicidade da doença auxiliando a compreender as diferentes formas da doença no modelo experimental / Paracoccidioidomycosis (PCM) is a systemic granulomatous disease caused by Paracoccidioides spp. (P. brasiliensis and P. lutzii), geographically, is limited to Latin America with endemic areas from Mexico to Argentina, as one of the systemic mycoses with the highest incidence in the region, mainly affecting rural workers. The largest number of patients with PCM has been mainly reported in Brazil, Colombia and Venezuela. The true incidence of this mycosis is underestimated in Brazil and little is known about the new species described - P. lutzii. Most studies in P. lutzii were focused on genetics, speciation and the generation of new antigens to improve the specificity and sensitivity of serological tests. Currently, traditional antigenic preparations, prepared with isolates of P. brasiliensis, are inefficient. There are few studies focused on P. lutzii biology and virulence factors that can be compared with P. brasiliensis in experimental models. Our study aimed to evaluate some in vitro and in vivo aspects related to pathogenicity: phagocytosis and intracellular killing of P. lutzii by peritoneal macrophages from knockouts (KO) for PRRs (TLR2, TLR4 and Dectin) and intracellular activators (MyD88 and NALP3). In addition, animals were infected with P. lutzii yeast and compared with the well-established models of infection with yeast cells (Pb18) and conidia (ATCC Pb60855) from P. brasiliensis. Our data indicate that similarly to what happens with the phagocytosis of P. brasiliensis, P. lutzii phagocytosis is dependent on TLR2, TLR4 and Dectin-1. Other molecules, involved in co-stimulation and presentation of antigens such as MHC II, CD80 and CD86 were also shown to participate in the P. lutzii-host interaction. However, intracellular killing of P. lutzii yeast cells was clearly dependent on TLR4, and the production of cytokines as IL-6, MIP-2, IFN- and IL-12p40 were important for the control of the yeast by macrophages. In the experimental model of P. lutzii, male C57BL/6 mice (6-7 weeks) were infected intratracheally with 1x106 viable yeasts of the isolate Pb01like. We found two phases of the disease, the first from the inoculation to 2 or 4 weeks after infection and the second from 4 to 12 weeks. Yeast appear to be contained within the first week of infection and subsequently are also absent from macerated lung, differently from the model of BALB/c mice infected with ATCC Pb60855 conidia in which CFUs were detected up to week 16 post-infection. We found a mixed Th1/Th2 pattern (IL-12p70, IL-23, IL-10) in bronchoalveolar lavage and lung, with the predominance of proinflammatory cytokines in the first phase and predominance of regulatory Th2 cytokines in the second phase, reproducing findings of P. brasiliensis infection models produced with both conidia and yeast. However, in the first period of the disease in C57BL/6 mice there was a higher inflammatory burden, reflected by the high cytokine levels (TNF-alpha, MIP-2 and GM-CSF), the latter in particular because it was positively regulated both in vitro and vivo), that persisted through the chronic period. We also observed that starting from 48 hours postinfection to the chronic period there were increased levels of IL-12p70, which together with IL-23 appeared to be responsible for the reduction of infection in the late period. This is the first time that an experimental model with P. lutzii (Pb01) is described, showing an immunological profile with only slight differences compared to the P. brasiliensis model. The present study details important aspects of the pathogenesis of the disease due to different species of Paracoccidioides and helps to understand the different forms of presentation in experimental models
42

Developing Maker Economies in Post-Industrial Cities: Applying Commons Based Peer Production to Mycelium Biomaterials

Rocco, Grant R 01 October 2015 (has links)
Our current system of research and production is no longer suitable for solving the problems we face today. As climate change threatens our cities and livelihoods, the global economic system preys on the weak. A more responsive, equitable, and resilient system needs to be implemented. Our post industrial cities are both products and victims of the boom-bust economies employed for the last few centuries. While some communities have survived by converting to retail and services based economies, others have not been so fortunate and have become run-down husks of their former bustling selves. The key to revitalizing these cities is to create new industries that empower people, unlike the service economies that deride and devalue them. Peer to Peer (P2P) development models like open source software communities create platforms for people to collaborate on projects and share resources. On the scale of cities, the goal is to stimulate the growth of closed loop, local, micro-economies that are inherently more stable than traditional, centralized economic models.Commons Based Peer Production (CBPP) is a term coined by Professor Yochai Benkler at Harvard Law School. It describes a new model of socio-economic production in which the labor of large numbers of people is coordinated (usually with the aid of the Internet) mostly without traditional hierarchical organization. It is based on low thresholds for participation, freely available modular tasks, and community verification of quality (peer governance). CBPP usually only applies to intellectual output, from software to libraries of quantitative data to human-readable documents (manuals, books, encyclopedias, reviews, blogs, periodicals, and more); however, this system can be adapted for physical manufacturing. A P2P system of development for material goods must be explored through the production of a common resource. Mycelium is the “roots” of fungi. It can be grown anywhere with agricultural refuse as a substrate. It has properties that make it ideal for building insulation and it is environmentally innocuous. It is Cradle to Cradle certified, and it requires little specialized equipment to produce. As a consumer product, it has had trouble gaining traction in a notoriously stubborn market dominated by hydrocarbon based market leaders like extruded polystyrene (XPS). Mycelium products are ripe for development as a regenerative building material. The goal is to increase the R-value of the material, decrease the cost of manufacturing, and carve out a market for this extraordinary product. The purpose of applying a CBPP approach is to increase the speed of development and aid in market penetration. The strategy is to decentralize manufacturing of and experimentation with the product. This requires a robust network of production nodes. Essentially, this involves setting up franchises in select markets (like the Pioneer Valley), where there is a strong interest in local, sustainable products. The nodes would be small cooperative businesses that are licensed to produce the material as well as collect data on the manufacturing and performance of mycelium insulation. The data will then be used to improve the production process. The bulk of the thesis is in designing one such node in Greenfield, MA, located adjacent to the new John W. Olver Transit Center on Bank Row St.
43

Observation et modélisation de la croissance de Postia placenta : de l'échelle discrète de la colonie à l'échelle macroscopique / Observation and modeling of the growth of the wood-decay fungus Postia placenta : scaling from discrete mycelial networks to macroscopic fungal development

Du, Huan 28 March 2017 (has links)
L’utilisation de matériaux d’origine végétale dans les bâtiments thermiquement performants pose la question de la pérennité des ouvrages principalement à cause de la dégradation fongique. Postia placenta est une espèce des champignons provoquant la pourriture brune, qui est la plus destructrice pour les constructions en bois.Ce travail se concentre sur l’observation et la modélisation de la croissance de Postia placenta à trois échelles successives : l'arborescence du mycélium (échelle discrète), la croissance en milieu libre (échelle continue) et la croissance en milieu encombré (échelle macroscopique). L’observation expérimentale de la croissance de Postia placenta utilise un microscope confocal à balayage laser pour quantifier les différentes mécanismes et obtenir les paramètres de croissance. A partir de cette observation, un modèle discret capable de générer un mycélium de forme extrêmement similaire à celle observée a été imaginé, développé et validé. Ensuite, à partir des profils de biomasse moyennés selon le rayon des mycéliums simulés par le modèle discret, un modèle continu basé sur une équation de réaction diffusion a été identifié pour décrire l’évolution de la concentration de biomasse fongique. Ce modèle continu offre la possibilité de la transition de l’échelle locale vers l’échelle macroscopique. Pour cela, des simulations de la prolifération en environnement encombré sont obtenues à l'aide du modèle continu. Par prise de moyenne, les champs spatio-temporels obtenus permettent de déterminer les paramètres d'un modèle continu similaire, mais valable à l'échelle macroscopique, sur un milieu fictif qui prend en considération la morphologie des obstacles. / The use of bio-based materials in thermally efficient buildings raises the question of the sustainability mainly due to fungal degradation. Among the wood-decay fungi, Postia placenta is one of the most common brown rot fungi, which are the most destructive due to their rapid decaying mechanisms. This work focused on the experimental observation and the modeling of fungal growth at three successive scales: the mycelial network (discrete scale), mycelial growth in homogeneous media (continuous scale) and mycelial growth in porous media (macroscopic scale).The experimental observation of the growth of Postia placenta was performed using confocal laser scanning microscopy to quantify the different growth mechanisms and obtain the growth parameters. A discrete model has been derived from this observation and is capable of generating mycelial networks extremely similar to the observed ones. A continuous formulation based on a reaction diffusion equation was developed from the radial biomass density of a mycelial network obtained in the discrete model. This continuous formulation was then used to derive an equivalent macroscale model able to account for fungal development in porous media. Simulations were performed on various periodic porous media. The parameters of the macroscale model was identified on the macroscopic fields obtained by averaging the local field over one periodic unit cell.
44

Produção de biomassa fúngica da linhagem PS-2001 de Pleurotus sajor-caju (Fr.) Singer em cultura submersa

Confortin, Fernanda Grison 24 November 2006 (has links)
Neste trabalho, formularam-se diferentes meios de cultivo para a produção econômica de biomassa de Pleurotus sajor-caju PS-2001 em processo submerso, visando o emprego do micélio na alimentação humana. Foram testadas glicose, frutose e sacarose como fontes de carbono, assim como diferentes concentrações de glicose, óleo de soja, solução de sais, extrato de levedura Prodex®, proteína de soja e sulfato de amônio. Estudos realizados em frascos agitados mostraram que 10g.L-1 de glicose promoveram a maior biomassa micelial (5,98g.L-1) e a melhor produtividade (0,048g.L-1.h-1). A adição de 1mL.L-1 de óleo de soja ao meio de cultivo mostrou ser favorável ao crescimento fúngico, também resultando na presença do aroma típico de corpos de frutificação. Os resultados de otimização do meio de cultivo mostraram que proteína de soja (2,3g.L-1), extrato de levedura (1,86g.L-1) e sulfato de amônio (1,57g.L-1) também favoreceram o crescimento. Estudos realizados em biorreator de bancada, utilizando o meio otimizado e nas condições testadas (temperatura de 28ºC, freqüência do agitador de 100rpm, taxa de aeração de 0,5vvm, O2 dissolvido acima de 30% da saturação), quando comparados aos resultados obtidos em frascos agitados com o mesmo meio, mostraram valores de biomassa, rendimento e produtividade superiores (8,18g.L-1, 0,82g.g-1 e 0,08g.L-1.h-1, respectivamente). Ao comparar os principais componentes do micélio seco de P. sajor-caju PS-2001, obtidos no presente trabalho, com o do corpo de frutificação da mesma linhagem, cultivado em serragem de eucalipto, observaram-se semelhanças na composição química com relação ao percentual de carboidratos totais, proteína bruta e minerais; no entanto, os conteúdos de lipídios brutos e de calorias mostraram-se maiores no micélio. O consumo total de sacarose na presença de óleo de soja foi evidenciado quando o cultivo foi realizado em biorreator, o que não ocorreu em frascos agitados. Ao comparar os resultados dos cultivos variando as fontes de carbono (glicose e sacarose) em biorreator, observaram-se maiores valores de biomassa, rendimento e produtividade com glicose. A determinação dos valores de exopolissacarídeos (EPS) correspondeu a 1,18 e 1,58g de matéria seca.L-1 após 120h e 144h, para glicose e sacarose, respectivamente. Os resultados mostraram ausência de atividade antioxidante in vitro dos EPS e do extrato bruto do micélio, avaliadas através da capacidade de redução do radical livre 1,1-difenil-2-picril-hidrazil (DPPH°). Verificou-se que, para produzir 1kg de micélio seco, utiliza-se 1,69kg de sacarose, a um custo de R$1,63, sendo o valor de kw.h-1 consumido de R$1,26, totalizando R$2,89, não computados os custos de mão de obra e de secagem; entretanto, o valor de mercado para 1kg de cogumelo seco é de R$200,00. / Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-05-14T17:08:22Z No. of bitstreams: 1 Dissertacao Fernanda G Confortin.pdf: 667228 bytes, checksum: dd5aee415908da35b7dd385fcbfcba0c (MD5) / Made available in DSpace on 2014-05-14T17:08:22Z (GMT). No. of bitstreams: 1 Dissertacao Fernanda G Confortin.pdf: 667228 bytes, checksum: dd5aee415908da35b7dd385fcbfcba0c (MD5) / In this study, different growth media for the economic production of biomass of Pleurotus sajor-caju PS-2001 in submerged process were formulated, aiming the use of mycelium in human feeding. Glucose, fructose and sucrose as carbon sources, as well as different concentrations of glucose, soy oil, salt solution, Prodex® yeast extract, soy protein and ammonium sulphate were tested. Studies that were carried out in shaken flasks showed that 10g.L-1 of glucose led to the larger mycelium biomass (5.98g.L-1) and the best productivity (0.048g.L-1.h-1). The addition of 1mL.L-1 of soy oil to the medium was favorable to fungal growth, also resulting in the presence of the typical aroma of the fruiting body. The results achieved in the optimization of the growing medium showed that soy protein (2.3g.L-1), yeast extract (1.86g.L-1) and ammonium sulphate (1.57g.L-1) enhanced the mycelium growth. Studies carried out in laboratory-scale bioreactor, using the optimized medium, under standard conditions (temperature of 28ºC, initial impeller speed of 100rpm, initial aeration rate of 0.5vvm, and dissolved oxygen over 30% of saturation), showed superior biomass values, yield, and productivity (8.18g.L-1, 0.82g.g-1 and 0.08g.L-1.h-1, respectively) when compared to the results obtained in shaken flasks with the same medium. By comparing the composition of the dry mycelium of P. sajor-caju PS-2001 obtained in this study with the fruiting body of the same strain, grown on eucalyptus sawdust, similarities in the chemical composition regarding the total carbohydrate percentual, crude protein and minerals were observed. However, the contents of crude lipids and calories were higher in the mycelium. The total consumption of sucrose in the presence of soy oil was evidenced when growth was carried out in bioreactor, which did not occurred in shaken flasks. When comparing the results of cultivation on media containing glucose and sucrose in bioreactor, superior values of biomass concentration, yield and productivity with glucose were observed. With media containing glucose and sucrose, exopolyssaccharide (EPS) values of 1.18 and 1.58g of dry material.L-1, after 120h and 144h, respectively, were observed. No in vitro antioxidant activity of both EPS and mycelium crude extract was detected when these materials were evaluated with respect to their capacity of reducing the free radical 1,1-difenil-2-picrilhidrazil (DPPH°). It was calculated that, to produce 1kg of dry mycelium, it is used 1.69kg of sucrose, costing R$1,63, being the value of kw.h-1 consumed of R$1,26, toting up R$2,89, not being computed the labor and drying costs; however, the market value for 1kg of dry mushroom is R$200,00.
45

Produção de biomassa fúngica da linhagem PS-2001 de Pleurotus sajor-caju (Fr.) Singer em cultura submersa

Confortin, Fernanda Grison 24 November 2006 (has links)
Neste trabalho, formularam-se diferentes meios de cultivo para a produção econômica de biomassa de Pleurotus sajor-caju PS-2001 em processo submerso, visando o emprego do micélio na alimentação humana. Foram testadas glicose, frutose e sacarose como fontes de carbono, assim como diferentes concentrações de glicose, óleo de soja, solução de sais, extrato de levedura Prodex®, proteína de soja e sulfato de amônio. Estudos realizados em frascos agitados mostraram que 10g.L-1 de glicose promoveram a maior biomassa micelial (5,98g.L-1) e a melhor produtividade (0,048g.L-1.h-1). A adição de 1mL.L-1 de óleo de soja ao meio de cultivo mostrou ser favorável ao crescimento fúngico, também resultando na presença do aroma típico de corpos de frutificação. Os resultados de otimização do meio de cultivo mostraram que proteína de soja (2,3g.L-1), extrato de levedura (1,86g.L-1) e sulfato de amônio (1,57g.L-1) também favoreceram o crescimento. Estudos realizados em biorreator de bancada, utilizando o meio otimizado e nas condições testadas (temperatura de 28ºC, freqüência do agitador de 100rpm, taxa de aeração de 0,5vvm, O2 dissolvido acima de 30% da saturação), quando comparados aos resultados obtidos em frascos agitados com o mesmo meio, mostraram valores de biomassa, rendimento e produtividade superiores (8,18g.L-1, 0,82g.g-1 e 0,08g.L-1.h-1, respectivamente). Ao comparar os principais componentes do micélio seco de P. sajor-caju PS-2001, obtidos no presente trabalho, com o do corpo de frutificação da mesma linhagem, cultivado em serragem de eucalipto, observaram-se semelhanças na composição química com relação ao percentual de carboidratos totais, proteína bruta e minerais; no entanto, os conteúdos de lipídios brutos e de calorias mostraram-se maiores no micélio. O consumo total de sacarose na presença de óleo de soja foi evidenciado quando o cultivo foi realizado em biorreator, o que não ocorreu em frascos agitados. Ao comparar os resultados dos cultivos variando as fontes de carbono (glicose e sacarose) em biorreator, observaram-se maiores valores de biomassa, rendimento e produtividade com glicose. A determinação dos valores de exopolissacarídeos (EPS) correspondeu a 1,18 e 1,58g de matéria seca.L-1 após 120h e 144h, para glicose e sacarose, respectivamente. Os resultados mostraram ausência de atividade antioxidante in vitro dos EPS e do extrato bruto do micélio, avaliadas através da capacidade de redução do radical livre 1,1-difenil-2-picril-hidrazil (DPPH°). Verificou-se que, para produzir 1kg de micélio seco, utiliza-se 1,69kg de sacarose, a um custo de R$1,63, sendo o valor de kw.h-1 consumido de R$1,26, totalizando R$2,89, não computados os custos de mão de obra e de secagem; entretanto, o valor de mercado para 1kg de cogumelo seco é de R$200,00. / In this study, different growth media for the economic production of biomass of Pleurotus sajor-caju PS-2001 in submerged process were formulated, aiming the use of mycelium in human feeding. Glucose, fructose and sucrose as carbon sources, as well as different concentrations of glucose, soy oil, salt solution, Prodex® yeast extract, soy protein and ammonium sulphate were tested. Studies that were carried out in shaken flasks showed that 10g.L-1 of glucose led to the larger mycelium biomass (5.98g.L-1) and the best productivity (0.048g.L-1.h-1). The addition of 1mL.L-1 of soy oil to the medium was favorable to fungal growth, also resulting in the presence of the typical aroma of the fruiting body. The results achieved in the optimization of the growing medium showed that soy protein (2.3g.L-1), yeast extract (1.86g.L-1) and ammonium sulphate (1.57g.L-1) enhanced the mycelium growth. Studies carried out in laboratory-scale bioreactor, using the optimized medium, under standard conditions (temperature of 28ºC, initial impeller speed of 100rpm, initial aeration rate of 0.5vvm, and dissolved oxygen over 30% of saturation), showed superior biomass values, yield, and productivity (8.18g.L-1, 0.82g.g-1 and 0.08g.L-1.h-1, respectively) when compared to the results obtained in shaken flasks with the same medium. By comparing the composition of the dry mycelium of P. sajor-caju PS-2001 obtained in this study with the fruiting body of the same strain, grown on eucalyptus sawdust, similarities in the chemical composition regarding the total carbohydrate percentual, crude protein and minerals were observed. However, the contents of crude lipids and calories were higher in the mycelium. The total consumption of sucrose in the presence of soy oil was evidenced when growth was carried out in bioreactor, which did not occurred in shaken flasks. When comparing the results of cultivation on media containing glucose and sucrose in bioreactor, superior values of biomass concentration, yield and productivity with glucose were observed. With media containing glucose and sucrose, exopolyssaccharide (EPS) values of 1.18 and 1.58g of dry material.L-1, after 120h and 144h, respectively, were observed. No in vitro antioxidant activity of both EPS and mycelium crude extract was detected when these materials were evaluated with respect to their capacity of reducing the free radical 1,1-difenil-2-picrilhidrazil (DPPH°). It was calculated that, to produce 1kg of dry mycelium, it is used 1.69kg of sucrose, costing R$1,63, being the value of kw.h-1 consumed of R$1,26, toting up R$2,89, not being computed the labor and drying costs; however, the market value for 1kg of dry mushroom is R$200,00.
46

Enzyme Activity and Antimicrobial Screening of Ambrosiella grosmanniae

Onyenobi, Ebuka Isaiah 02 September 2021 (has links)
No description available.
47

Population biology of Cryphonectria parasitica infected with Cryphonectria hypovirus 1 on American chestnut trees

Hogan, Eric Philip 28 November 2006 (has links)
In the early 1900's the American chestnut (Castanea dentata (Marsh.) Borkh.) was nearly destroyed by the introduction of the orange-pigmented, chestnut blight fungus (Cryphonectria parasitica (Murr.) Barr). Chestnut blight is less severe in Europe, where hypovirulent (= reduced virulence) strains of the fungus are found to be associated with healing cankers. These European hypovirulent strains are infected with a dsRNA virus, Cryphonectria hypovirus 1 (CHV1), and have a white phenotype when grown in culture. Transmission of CHV1 in C. parasitica is limited by incompatibility between isolates in different vegetative compatibility (vc) types. In 1982-83, naturally formed blight cankers on American chestnut grafts, derived from large survivors, were inoculated with a mixture of four European (white) hypovirulent strains of C. parasitica. After 14 years the white strains were recovered throughout the inoculated grafts, which had low levels of blight damage. CHV1 had infected at least 45 new vc types, and was present in four different fungal colony morphology groups, including one type that had intermediate or partial pigmentation. However, CHV1 was unable to move throughout a single vc type within a natural canker. The objectives of this study were: 1) to determine the frequency and phenotypic diversity of CHV1-infected C. parasitica isolates recovered from stromata and canker tissue from natural cankers on the grafted American chestnut trees and artificially established cankers on forest American chestnuts; 2) to determine the presence or absence of CHV1 in intermediate-pigmented isolates recovered from the American chestnut research plots; 3) to investigate the roles of colony age, resistance to hypovirus infection, and functional mycelial units in the failure of CHV1 to move throughout a vc type of C. parasitica in vitro, and; 4) to examine the role of low temperatures and a high elevation topographic site on CHV1 survival within C. parasitica colonies in vivo and in vitro. The results indicated that there was no direct correlation between the amount of colony pigmentation and the presence of dsRNA. Within each of the three colony phenotype categories (pigmented, intermediate and white), several C. parasitica isolates tested positive for the presence of CHV1. This presence of CHV1 in intermediate isolates, coupled with the relatively large number of intermediate isolates collected from stromata on cankers, indicates that intermediate isolates may perform an important, and previously overlooked, function in biological control of chestnut blight. In this study, all CHV1 movement trials indicated that the age of the C. parasitica colony limited the movement of CHV1 throughout the colony. The majority of the CHV1 movement through a C. parasitica colony occurred between 0 and 7 days following challenge with an isogenic CHV1-infected strain. Isolation data using a lattice grid did not indicate a consistent pattern of CHV1 movement throughout a C. parasitica colony. Low temperatures associated with high altitude had no effect on hypovirus survival in vivo or in vitro. Additionally, no long-term C. parasitica resistance to CHV1 infection or movement was identified in this study. This research has identified new insights into CHV1 spread and survival that may be important in understanding the role of CHV1 in the biological control of chestnut blight. / Ph. D.
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Развој и примена биокомпозитног плочастог термоизолационог материјала на бази биомасе и мицелијума гљива / Razvoj i primena biokompozitnog pločastog termoizolacionog materijala na bazi biomase i micelijuma gljiva / Development and utilisation of biocomposite thermal insulation panels based on biomass and mushroom mycelium

Maoduš Nikola 08 October 2019 (has links)
<p>Истраживање у оквиру докторске дисертације обухвата анализу могућности производње и примене биокомпозитних термоизолационих плоча заснованих на нуспроизводима пољопривредне производње и мицелијума гљиве буковаче као везивног средства. Циљеви истраживања су развој методе за производњу биокомпозитних термоизолационих материјала и утврђивање морфолошких, физичко-хемијских, механичких и хигротермичких својстава биокомпозита. У складу са резултатима истраживања и закључцима да је могуће произвести и користити биокомпозитни термоизолациони материјал заснован на биомаси и мицелијуму гљива изведена је анализа енергетске ефикасности и животног циклуса материјала. Резултати истраживања представљају значајну полазну основу за производњу и даље унапређење биокомпозитних термоизолационих материјала у грађевинарству, са позитивном оценом мицелијума гљива као везивног средства.</p> / <p>Istraživanje u okviru doktorske disertacije obuhvata analizu mogućnosti proizvodnje i primene biokompozitnih termoizolacionih ploča zasnovanih na nusproizvodima poljoprivredne proizvodnje i micelijuma gljive bukovače kao vezivnog sredstva. Ciljevi istraživanja su razvoj metode za proizvodnju biokompozitnih termoizolacionih materijala i utvrđivanje morfoloških, fizičko-hemijskih, mehaničkih i higrotermičkih svojstava biokompozita. U skladu sa rezultatima istraživanja i zaključcima da je moguće proizvesti i koristiti biokompozitni termoizolacioni materijal zasnovan na biomasi i micelijumu gljiva izvedena je analiza energetske efikasnosti i životnog ciklusa materijala. Rezultati istraživanja predstavljaju značajnu polaznu osnovu za proizvodnju i dalje unapređenje biokompozitnih termoizolacionih materijala u građevinarstvu, sa pozitivnom ocenom micelijuma gljiva kao vezivnog sredstva.</p> / <p>Research in the thesis is focused on development and utilisation of<br />biocomposite thermal insulation panels based on agricultural biomass and<br />oyster mushroom mycelium as a binding agent. The goals of the research are<br />development of production method of biocomposite thermal insulation panels<br />and determination of morphological, physical-chemical, mechanical and<br />hygrothermal properties of the biocomposite. Energy efficiency and life cycle<br />assessment were conducted in accordance with the research results and<br />conclusions that it is possible to manufacture and use the biocomposite<br />thermal insulation panels based on biomass and mushroom mycelium. The<br />research results represent significant starting point for manufacturing and<br />further improvement of biocomposite thermal insulation panels used in civil<br />engineering and confirm the use of mycelium as a binding agent.</p>
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Analyse transcriptomique de deux souches fongiques québécoises Inonotus obliquus et Armillaria sinapina

Fradj, Narimane January 2019 (has links) (PDF)
No description available.
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Growing Furniture : Designing a mycelium side table

Hedrén, Sam, Andersson, Noah January 2023 (has links)
Product development can be taxing for the environment. When it comes to hardware products then a lot ofthe materials generally involved are based on finite resources such as fossil fuels. As the most commonlyused materials are rarely biodegradable, they often end up in landfills where they end up being harmfulboth to the environment and its inhabitants for a very long time. During recent years some companieshave started combating this through getting involved in the development and implementation of moresustainable alternatives. One of these companies trying to implement more sustainable materials isInteresting Times Gang, who now also wishes to develop new products by using mycelium - theunderground network of threads produced by fungi. This as mycelium poses a lot of sustainable propertiessuch as biodegradability, a high degree of moldability as well as being a cultivated resource rather thanbeing synthetic. This project serves to investigate what kind of product types are fitting for myceliumcomposites per request from ITG, as well as what kind of surface treatments are possible and fitting tomake the material more desirable. This with the intention of increasing awareness about the material withthe hopes of promoting it to a larger audience, enabling a transition towards more sustainable materialalternatives in the process. With the information gathered through research the project resulted in a sidetable that was designed and manufactured as a 1:1 scale prototype to showcase the possibilities of thematerial. This was done through a material driven design process which was divided into four steps:Understanding the material, Creating materials experience vision, Manifesting materials experience visionand Designing product concepts. Each phase included its own methods respectively and some of themethods include literature review, material testing, benchmarking, user testing, digital prototyping andmanufacturing to name a few. The project is a master thesis for the Industrial Design Engineeringprogramme at Luleå University of Technology performed during the spring of 2023.

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