Os efeitos das queimadas na Amazônia em nível celular e molecular

The Amazon holds over half of the planet's remaining tropical forests and comprises the largest biodiversity in the world, accounting for approximately 60 % of the Brazilian territory. However, deforestation fires in the region causes serious problems to exposed human. The aim of this study was to evaluate the chemical compounds as well as the cellular and molecular effects after exposure to organic material extracted from particulate matter less than 10 µm (PM10) in the Amazon region. As for the chemical composition, n-alkanes analysis showed a prevalence of anthropogenic influence during the fires in the region. In addition, there was a predominance of monosaccharides from biomass burning markers. Also, the Polycyclic Aromatic Hydrocarbons (PAH) and their derivatives have also been identified in samples collected in the Amazon. By using the PAH concentrations was possible to calculate the BaP-equivalent and it was found that the dibenz(a) anthracene contributes with 83% to potential carcinogenic risk. As for the potential mutagenic risk, the benzo (a) pyrene is the HPA that has a major contribution in this analysis. It may be noted that the retene was the most abundant PAH. This compound was genotoxic and cause death by necrosis in the human lung cells. In biological tests, the data showed that organic PM10 is capable of causing genetic damage in both plant cells and in human lung cells. This damage cause an arrest in the G1 phase of the cell cycle exposed, increasing the expression of p53 and p21. Additionally, the PM10 caused cell death by apoptosis, increasing the foci of histone - H2AX. Given these results, it is important to emphasize the reduction and better control of biomass burning in the Amazon region thus improving the quality of health of the population being exposed. As clearly stated recently by the World Health Organization, the reduction of air pollution could save millions of lives annually.

A biotecnologia na propagação e conservação do umbuzeiro (Spondias tuberosa Arr. Cam.) e percepção sobre sua importância por agricultores da comunidade Malhada Vermelha, Campo Redondo (RN-Brasil)

The umbu tree (Spondias tuberosa Arruda) is a fruit native to the northeast of Brazil with great economic, social and ecological importance for the northeastern semi-arid region. Despite its role, the umbu tree has suffered negative pressure thanks to cluttered extractivism and to negative selection of its fruits, which as the deforestation and the dormancy of seeds contribute to the decrease of its production year after year, making necessary studies that contribute to the improvement of this specie and its conservation. Given the risks to the conservation of the specie and its usefulness to the population, the association between plant biotechnology, for being a tool that can be used to increase its production. and the perception of gathering communities, by valuing the point of view and the knowledge of the population, can facilitate its conservation. This work aimed to develop methods of propagation for umbu tree as well as contribute to its conservation by using biotechnology, with specific objectives to contribute to the conservation of this species; determine concentrations of BAP and ANA in the formation of buds; testing the efficiency of different substrates and concentrations of gibberellic acid on germination in vitro and ex vitro, as well as capture the perception of families in communities that engage in the gathering of umbu. To study the germination, the seeds were inoculated in different substrates (vermiculite, vermiculite + clay, clay, clay + manure and manure + vermiculite) and in different concentrations of gibberellic acid (0 mg, 250 g and 500 mg). For the formation of buds BAP to 0.1 mg-1 was associated with different concentrations of ANA (0.2; 0.4; 0.8mg.L-1). The study of perception was conducted by applying semi-structured questionnaire with Malhada Vermelha community. The experiments resulted in vermiculite and concentration of 500 mg gibberellic acid as the best for germination. The association of 0.1 mg.L-1 of BAP to 0.2 mg.L-1 of ANA provided better formation of buds. As to the application of questionnaires, they revealed that the population understands the decreased amount of umbu plants and umbu fruit in the region, as well as shows concern for its conservation.

Propagação in vitro de barueiro (Dipteryx alata Vog.)

Savannah is the second biome in biodiversity in Brazil, presenting great vegetation endemism. Dipteryx alata Vog. (Fabaceae), native from this biome, is an economically important species, with an incipient market due to the lack of commercial plantations. This highlights the need to develop and provide the basis for the domestication of this species. Thus, this study determined the best conditions for in vitro establishment, multiplication, elongation and rooting of stem tips of D. alata plantlets grown vitro. Two culture media (MS and WPM) were evaluated in different salt concentrations (25, 50, 75 and 100%) for plantlet establishment. Four concentrations of 6– Benzylaminopurine (BAP) (0, 1, 2, 3 and 4 mg L-1) amended with 0.25 mg L-1 naphthalene-acetic acid (NAA) were studied for multiplication. Simultaneous elongation and rooting were studied with four concentrations of NAA (0, 1, 2, 3 and 4 mg L-1) together with 0.5 mg L-1 IBA. The variables analyzed were: shoot length (CPA), root length (CP), fresh matter (MF), dry matter (MSC), stem diameter (DC) and number of leaves (NF), 120 days after inoculation, with the exception of number of shoots, which was evaluated in the multiplication stage only. The medium MS at the original salt concentration (100%) was effective for the in vitro establishment of E. alata, resulting in greater root length (27.65 cm) and number of leaves per plantlet (26.0). The concentration of 4 mg L-1 BAP was the best one for multiplication; however, greater concentrations can boost multiplication. The effect of NAA and IBA were noticeable on in vitro elongation and rooting, with best CPA (3.14 cm) and CR (15.84 cm). Therefore, it is possible to state that the medium MS increases the success probability of in vitro establishment of stem tips of Dipteryx alata. NAA concentrations below 3 mg L-1 were favorable for in vitro development of the species, with essential characteristics for acclimatization success|.

New constraints on micro-seismicity and stress state in the western part of the North Anatolian Fault Zone : Observations from a dense seismic array

Major funding was provided by the UK Natural Environment Research Council (NERC) under grant NE/I028017/1 and partially supported by Boğaziçi University Research Fund (BAP) under grant 6922. We would like to thank all the project members from the University of Leeds, Boğaziçi University, Kandilli Observatory, Aberdeen University and Sakarya University. I would also like to thank Prof. Ali Pinar and Dr. Kıvanç Kekovalı for their valuable comments. Some of the figures were generated by GMT software (Wessel and Smith, 1995).

New constraints on micro-seismicity and stress state in the western part of the North Anatolian Fault Zone : Observations from a dense seismic array

Major funding was provided by the UK Natural Environment Research Council (NERC) under grant NE/I028017/1 and partially supported by Boğaziçi University Research Fund (BAP) under grant 6922. We would like to thank all the project members from the University of Leeds, Boğaziçi University, Kandilli Observatory, Aberdeen University and Sakarya University. I would also like to thank Prof. Ali Pinar and Dr. Kıvanç Kekovalı for their valuable comments. Some of the figures were generated by GMT software (Wessel and Smith, 1995).

Producción de microtubérculos de papa (Solanum tuberosum L.), cultivar Burren en biorreactores económicos de inmersión temporal

El estudio de microtuberización del cultivar de papa Burren se realizó en el Laboratorio de Cultivo de Tejidos de la Universidad Nacional Agraria entre los meses de junio a diciembre del 2015. Se estudiaron las fases de multiplicación y formación de microtubérculos en Biorreactores Económicos de Inmersión Temporal (BEIT). En la fase de multiplicación se evaluó la formación de plantas completas cuando se sembraron 70 microesquejes en cinco variantes de medios de cultivo. Se empleó un diseño de Bloques Completos al Azar con arreglo unifactorial con réplicas conformadas por 2 BEIT, y para definir las diferencias estadísticas entre las medias (ANDEVA) de los tratamientos se realizó la prueba de rangos múltiples de Duncan-Waller ( = 0.05). En la formación de plantas se evaluaron la longitud de plantas, número de hojas y número de brotes que se les realizó la prueba de medias de diferencia mínima significativa con α = 0.05, se calculó el porcentaje de supervivencia. Como resultado se obtuvo en las variantes de medios de cultivo que contenían 0.20 mg l-1 de GA3 con 0.50 mg l-1 de BAP y 0.10 mg l-1 de GA3 con 1 mg l-1 de BAP, se obtuvieron medias respectivas en número de entrenudos de 6.32-5.7 y en número de hojas por planta de 7.37-6.93. Adiciones de sacarosa de 80 g l-1 y 110 g l-1 favorecieron la formación de microtubérculos de peso fresco con medias entre 0.69-0.75 gramos. La adición de sacarosa entre 80 g l-1 y 120 g l-1 no se registró diferencias estadísticas significativas entre las medias de las variables diámetro y longitud de microtubérculos. Con microtubérculos con diámetro mayor a los 10 mm se obtuvieron medias en longitud de planta, número de hojas y número de brotes de 21, 16.35 y 5.65 cm respectivamente y con diámetros entre 8-10 mm las medias respectivas fueron de 16.37, 11.35 y 5.35 cm.

Microtuberización del cultivar de papa (Solanum tuberosum L.) Banba en biorreactores económicos de inmersión temporal

El trabajo se realizó en el laboratorio de cultivo de tejidos de la Universidad Nacional Agraria (UNA) de mayo a septiembre de 2015. El mismo pretende sentar las bases de la producción de semilla básica con un método innovador, al producir microtubérculos de papa del cultivar Banba en BEITs y determinar la mejor variante de medio de cultivo en la fase de multiplicación y microtuberización. Se buscaron las características morfológicas deseadas, mediante el efecto de cinco variantes de medios de cultivos (0.10 y 0.20 mg l -1 de GA3 con 0.5 y 1 mg l -1 de bencilaminopurina (BAP)). Posteriormente se utilizaron cinco variantes de medios con BAP para la etapa de microtuberización en BEIT con 3000 ml de medio de cultivo en condiciones de crecimiento de 20 ± 3 °C, 16 horas luz y 8 de oscuridad con intensidad de luz de 2000 lux. El ensayo se estableció en BCA unifactorial con tres repeticiones. Para determinar las diferencias estadísticas entre las medias de los tratamientos se realizó la prueba de medias de diferencia mínima significativa (LSD) de Fisher con (α = 0.05). En los medios de multiplicación para las características altura de planta y número de brotes axilares, presentó mejor desempeño el medio con 0.10 mg l -1 de GA3 y 0.50 de BAP. Para el número de entrenudos no hubo diferencias significativas y para el número de hojas la mejor respuesta se obtuvo con 0.10 mg l -1 de GA3 y 0.50 g l -1 de BAP. En microtuberización se obtuvieron buenos resultados en microtubérculos por planta, diámetro y longitud en el medio de cultivo con 1 mg l -1 de BAP y 11% de sacarosa, así como microtubérculos esféricos superiores a los 0,6 g de peso en 36%.

Adubação de sistemas: antecipação de adubação nitrogenada para a cultura do milho em integração lavoura-pecuária

Traditionally in no-tillage systems, fertilization is done to the catch crop. In general nutrient cycling in crop systems has not been treated as an important tool in the process of nutrient supplying for plants. The type and the condition in which vegetable residuesis decomposed can affect the efficiency of nutrient cycling.This study assessed the effect of anticipated nitrogen fertilization in crop-livestock systems on cultivated cornproduction, rate ofnutrient release from plant residue, and theN-minerallevels of soil. The study was carried out in the city Abelardo Luz (SC) in a Clayey Oxisol. The experimental design was a randomized block design with three replications. The treatments were arranged in a 2 x 2 factorial arrangement. The first factor was N Fertilization Time: in the N-Pasture level, nitrogen (200 kg ha-1 N) and N-Grains level, no nitrogen was applied. The second factor was the Grazing Height, characterized by two sward heights of oat at 15 cm (Low Height Pasture) and at 30 cm (High Height Pasture). Corn hybrid ‘Máximus’ was sowed in 10thOctober, 31 days after the removal of animals. In the twelve resulting plots from the combination of treatments on pasture phase (N Fertilization Time x Grazing Height) rates of N-fertilizer (0, 100, 200 e 300 Kg ha-1 of N) as urea were allocated in the split plot.We conclude that anticipated N fertilization of winter cover crop pasture to provide high-quality forage and carry-over N to the subsequent corn crop and may eventually replace side drees nitrogen fertilization on corn and can improve overall N fertilizer efficiency use in integrated crop-livestock systems.The rate of K release from plant residues is very fast, releasing large quantities in the first days after plant desiccation.Despite of considerably high nitrogen dose used in both the pasture and at the grain crop it was not observed nitrate leaching risks during the study period.

Increased frequency of the autism broader phenotype in mothers transmitting etiological CNVs to sons affected by Autism Spectrum Disorder (ASD)

Autism Spectrum Disorder (ASD) is a frequent and complex neurodevelopmental disorder, characterized by impairments in social communication and repetitive behaviors and with a high male to female ratio: ~4:1. Genetic factors, including rare Copy Number Variants (CNVs), have a substantial impact in ASD risk1, and are associated with specific phenotypic manifestations2. Recent studies reported that rare inherited CNVs are enriched in mothers of ASD children compared with mothers of controls and are preferentially transmitted from mothers to ASD children suggesting a sex bias in CNV transmission; further, the imbalanced transmission of small pathogenic CNVs from unaffected mothers to their sons with ASD has been described3,4. An increased prevalence of autism-like personality traits is found in unaffected relatives of ASD children, suggesting a genetic liability of a broader autism phenotype (BAP)5. The BAP in parents of autistic children can be assessed by the Social Responsiveness Scale (SRS)6 and Broad Autism Phenotype Questionnaire (BAPQ)7 reports. The SRS is 65-item questionnaire to identify sub-clinical social impairments and interpersonal behaviour in individuals. The BAPQ is a 36-item questionnaire measures social aloofness, rigid personality, and pragmatic language deficits in both parents and children.

MULTIPLICAÇÃO E ALONGAMENTO IN VITRO DE CLONES HÍBRIDOS DE Eucalyptus globulus

Os híbridos de Eucalyptus globulus representam uma excelente alternativa para o setor de celulose e papel, em razão dos ganhos em qualidade da madeira para a fabricação de celulose. Entretanto, estes híbridos têm apresentado recalcitrância ao enraizamento adventício. Assim, a micropropagação é apontada como a técnica para o rejuvenescimento desses híbridos adultos, viabilizando a propagação clonal dos mesmos. O presente trabalho avaliou o cultivo in vitro de três clones de Eucalyptus grandis x Eucalyptus globulus e de três clones de Eucalyptus urophylla x Eucalyptus globulus, em relação à multiplicação in vitro, no meio MS suplementado com 0,5 mg L-1 de BAP e 0,01 mg L-1 de ANA, bem como o efeito das concentrações de 0,25; 0,50; 0,75 e 1,0 mg L-1 de AIB e dos meios de cultura MS e JADS no alongamento in vitro das brotações. Os clones diferiram quanto à multiplicação in vitro das brotações e apresentaram uma taxa de multiplicação média dos clones de 3,0 tufos de brotações em cada subcultivo, ao longo dos 25 subcultivos realizados. No alongamento in vitro, os clones diferiram quanto às concentrações de AIB adequadas para provocar o alongamento, bem como em relação aos meios de cultura MS e JADS. O intervalo médio entre 0,40 e 0,80 mg L-1 de AIB proporcionou o maior número e comprimento das brotações alongadas in vitro e com maior vigor.

Establecimiento de un protocolo para el inicio del cultivo In Vitro de Agave letonae (Henequén) a partir de yemas axilares

La presente investigación se realizó en el Laboratorio de Biotecnología del Centro Nacional de Tecnología Agropecuaria y Forestal “Enrique Álvarez Córdova” (CENTA), con el objetivo de establecer un protocolo para el inicio del cultivo In Vitro de Agave letonae (henequén) a partir de yemas axilares. Se evaluaron tres tratamientos de esterilización superficial y en el establecimiento In Vitro se evaluó la combinación de reguladores de crecimiento como 6-bencilaminopurina (BAP) y ácido indolbutírico (AIB) en diferentes concentraciones en medio basal Murashige y Skoog (1962). En la fase de esterilización superficial de yemas axilares, el análisis de varianza al 0.01%, no detectó diferencia estadística altamente significativa entre tratamientos, por lo que la desinfección de yemas axilares puede realizarse con cualquiera de los tres tratamientos evaluados. En la fase de establecimiento In Vitro el análisis de varianza al 0.01%, mostró diferencia estadística altamente significativa entre tratamientos, por lo que se determinó que el tratamiento T2 constituido por medio de cultivo MS basal, suplementado con 1.0 mg/l de BAP y 0.5 mg/l de AIB; aceleró la brotación de yemas axilares a los 32 días promedio de la siembra In Vitro; se obtuvo un porcentaje promedio de brotación de 40%; se formaron brotes bien desarrollados que presentaron coloración verde oscura

Efecto del tipo de explante, regulador de crecimiento y medio de cultivo sobre la capacidad morfogénica de jatropha curcas L.

La especie Jatropha curcas L., comúnmente conocida en México como piñoncillo, es una planta productora de aceite que ha recibido gran atención en recientes años al utilizarse como fuente de energía por su gran potencial para la elaboración de biodiesel. Sin embargo, su introducción mundial como especie bioenergética se ha dado con diferentes grados de éxito debido al heterogéneo rendimiento de semillas y contenido de aceite como consecuencia de su amplia variabilidad genética. Esto ha impulsado la selección de genotipos elite, los cuales deben contar con un protocolo de propagación clonal por medio del cultivo de tejidos vegetales para acelerar el desarrollo de cultivares. La mayoría de los estudios morfogénicos se han hecho a partir de explantes de genotipos procedentes de la India, de modo que es necesario el estudio de los factores que afectan la morfogénesis en genotipos mexicanos, debido a la amplia variación genética. Los objetivos del presente estudio fueron: i) evaluar la expresión morfogénica de explantes bajo diferentes niveles de reguladores de crecimiento (thidiazurón, 6- bencilaminopurina y ácido indol-3-butírico) en dos medios de cultivo (Yasuda y MS), ii) estudiar la respuesta de explantes por efecto de 500 mg L-1 de polivinilpirrolidona (PVP) en la etapa de establecimiento in vitro de dos genotipos de Jatropha curcas (INI-3 e INI-6), y iii) determinar el comportamiento de la enzima polifenol oxidasa (PPO) en explantes de hoja y peciolo de dos genotipos de Jatropha curcas (INI-3 e INI-6) bajo la aplicación de hipoclorito de sodio (NaClO) al 3.24 % como agente desinfectante. En la etapa de establecimiento in vitro se evaluó el efecto del PVP en explantes de hoja y peciolo de los genotipos INI-3 e INI-6 bajo un diseño completamente al azar (DCA) con un arreglo factorial 2x2 con 90 repeticiones por tratamiento y un explante por unidad experimental, donde en el factor A fueron los genotipos (INI-3 e INI-6) y el factor B las dosis de PVP (control y 500 mg L-1). Las variables evaluadas en una prueba de ji-cuadrada fueron: viabilidad y presencia de callo, mientras que el peso de callo se evaluó por un análisis de varianza. En la etapa de inducción se analizaron los medios de cultivo Yasuda y MS más la interacción con diferentes dosis de thidiazurón (1.5 y 3.0 mg L−1), 6-bencilaminopurina (1.5 y 3.0 mg L−1), y (AIB) ácido indol-3-butírico (0.0, 0.5 y 1.0 mg L−1) en explantes de peciolo del genotipo INI-6, bajo un DCA con arreglo factorial 2x2x2x3 con tres repeticiones, compuestas de dos explantes por unidad experimental, donde la variable presencia de callo fue evaluada en un análisis de regresión logística. La determinación de la actividad de PPO se realizó bajo un DCA con arreglo factorial 2X2X2 con tres repeticiones, donde en el factor A fueron las dosis de NaClO (control y 3.24 %), el factor B los tipos de explantes (hoja y peciolo) y el factor C los genotipos (INI-6 e INI-3). Los resultados del establecimiento in vitro mostraron que únicamente el explante de peciolo fue viable al cultivo, revelando que los genotipos de estudio no presentan asociación con las frecuencias de explantes viables de acuerdo con las pruebas de ji-cuadrada. En esta misma etapa se encontró que la viabilidad de explantes varió según la posición del peciolo con base en el ápice terminal, donde los explantes del segundo nudo presentaron la mayor viabilidad con base en una prueba de jicuadrada. Además, la adición de PVP aumentó la viabilidad de explantes de peciolo e indujo la proliferación de callo con una diferencia significativa en la producción de callo fresco entre genotipos según el análisis de varianza. En la etapa de inducción se encontró que los factores AIB y TDZ además de las interacciones “TDZ*AIB” y “TDZ*BAP*AIB” están relacionadas significativamente con la presencia de callo y ningún tratamiento indujo el desarrollo de brotes a las ocho semana de cultivo in vitro. En la determinación de la actividad de PPO, se encontró que estadísticamente la aplicación de NaClO al 3.24 % causa el aumento en la actividad de PPO, además se descubrió diferencias estadísticas entre explantes y genotipos de estudio.

Características genotípicas de Staphylococcus coagulase-negativos e taxas de cura da mastite ovina.

A mastite em ovelhas de dupla aptidão é reconhecida por afetar a qualidade do leite. Staphylococcus coagulase-negativos (SCN) são os principais micro-organismos responsáveis pela doença, e o tratamento ao final da lactação, pode contribuir para a cura e prevenção de casos subclínicos na lactação consecutiva. Entretanto, fatores de virulência e mecanismos de resistência apresentados por SCN podem reduzir as taxas de cura. Os objetivos deste trabalho foram identificar no leite de ovelhas tratadas e não tratadas à secagem com antimicrobianos, as espécies de SCN antes e após o tratamento e identificar nesses micro-organismos a presença dos genes mecA, icaA, icaC, icaD, bap, bhp, sea, seb, sec, sed e tsst-1, determinar o perfil clonal das principais espécies identificadas e relacionar os casos de cura após o tratamento com a presença/ausência dos respectivos genes. Sessenta ovelhas foram divididas em três grupos experimentais: G1, controle, metades mamárias que não receberam antimicrobiano; G2, metades mamárias em que foram administrados 10 mL de cloxacilina-benzatina 100 mg via intramamária / estrutura convencional; G3, metades mamárias em que foram administrados 86 mL de cloxacilina-benzatina 50 mg via intramamária / estrutura nanoencapsulada. As amostras de leite foram coletadas à secagem e aos 15 e 30 dias pós-parto da lactação seguinte. As análises para identificação das espécies de SCN foram realizadas por meio de testes bioquímicos e Internal Transcribe Spacer (ITS-PCR), e a pesquisa dos genes responsáveis pelos fatores de virulência e pela resistência à oxacilina foram realizados por meio da técnica de reação em cadeia de polimerase (PCR). Dentre as espécies identificadas S. warneri prevaleceram nos três grupos experimentais. Nenhuma amostra foi positiva para o gene mecA. O único gene relacionado com a produção de enterotoxinas encontrado foi o sec. Dentre os genes relacionados com a produção de biofilme, icaD foi o único identificado nos três grupos experimentais. Staphylococcus warneri, S. simulans e S. epidermidis apresentaram clones na mesma metade mamária no pré e pós-parto das ovelhas. A cloxacilina benzatina nanoparticulada 50mg / 86 mL foi eficiente para reduzir a mastite subclínica no pós-parto de ovelhas (P= 0,0192). Staphylococcus warneri, S. simulans, S. epidermidis e S. xylosus foram as espécies de maior ocorrência. Os genes icaA, icaC, icaD e bap foram encontrados no momento da desmama e no pós-parto, os genes sec e icaD estão associados à ausência de cura da mastite subclínica no pós-parto. Ovelhas em que foram isolados SCN portadores de genes responsáveis pela formação de biofilme não apresentaram resultados satisfatórios quando submetidas a esquemas de controle e ao tratamento da mastite subclínica. Os genes sec e icaD, estão associadas à ausência de cura microbiológica da mastite subclínica no pós-parto. Staphylococcus epidermidis e S. xylosus portador do gene bap estão associados à reinfecção.

Germinação de sementes e otimização de técnicas de micropropagação de umbuzeiro (spondias tuberosa, arr.) anacardiaceae

The brazilian-plum (Spondias tuberosa, His) is a tropical fruit tree that has been consolidated in the market for agribusiness processing, due to its characteristic flavor of fruit. Accordingly, studies to optimize the propagation of plants are necessary for production of seedlings with agronomic and quality assurance measures. This study aimed at determining the efficient techniques for uniform seed germination, as brazilian-plum seed present mechanical dormancy, and establish optimal culture media for multiplication of shoots from the in vitro micropropagation. Firstly, in a greenhouse at the Universidade Federal do Rio Grande do Norte, was evaluated the influence of different methods of breaking dormancy in the emergence of seedlings of brazilian-plum and speed of germination (IVG) of seeds. After 60 days of cultivation, it was found that splay in the distal portion of the seed was the best treatment, with rates of 85.33% in germinability and 3.415 of IVG, compared with the treatment of seed-soaking in water for 12h + humus and the control group. Subsequently, new sources of seedling explants were obtained in studies of tissue culture. Laboratory of Plant Biotechnology that the university, was used stem apex, nodal segments and internodes in search of decontamination with various concentrations of calcium hypochlorite [Ca(OCl)2] and micropropagation, inoculating them in half WPM (1980) with various concentrations of 6-benzylaminopurine (BAP). We used 10 sample units with three replications for different concentrations of [Ca(OCl)2], BAP and explants type. After thirty days, which was observed for the control of contamination, during the establishment in vitro, concentrations of [Ca(OCl)2] between 0.5% and 2.0% were effective in combating exogenous contamination of the apex. In nodal segments and internodes, concentrations of [Ca(OCl)2] between 1.0% and 2.0% and 1.5% and 2.0% were respectively, sufficient to reduce the percentage of losses in these infestations explants. For micropropagation, the culture medium supplemented with 0.1 mg.L-1 BAP promotes better development of multiple shoots per explants from nodal segment. However, success does not get to shoot training in internodal segment

Performance of concrete incorporating amorphous silica residue and biomass fly ash

L'industrie du ciment est l'une des principales sources d'émission de dioxyde de carbone. L'industrie mondiale du ciment contribue à environ 7% des émissions de gaz à effet de serre dans l'atmosphère. Afin d'aborder les effets environnementaux associés à la fabrication de ciment exploitant en permanence les ressources naturelles, il est nécessaire de développer des liants alternatifs pour fabriquer du béton durable. Ainsi, de nombreux sous-produits industriels ont été utilisés pour remplacer partiellement le ciment dans le béton afin de générer plus d'économie et de durabilité. La performance d'un additif de ciment est dans la cinétique d'hydratation et de la synergie entre les additions et de ciment Portland. Dans ce projet, deux sous-produits industriels sont étudiés comme des matériaux cimentaires alternatifs: le résidu de silice amorphe (RSA) et les cendres des boues de désencrage. Le RSA est un sous-produit de la production de magnésium provenant de l'Alliance Magnésium des villes d'Asbestos et Thedford Mines, et les cendres des boues de désencrage est un sous-produit de la combustion des boues de désencrage, l'écorce et les résidus de bois dans le système à lit fluidisé de l'usine de Brompton située près de Sherbrooke, Québec, Canada. Récemment, les cendres des boues de désencrage ont été utilisées comme des matériaux cimentaires alternatifs. L'utilisation de ces cendres comme matériau cimentaire dans la fabrication du béton conduit à réduire la qualité des bétons. Ces problèmes sont causés par des produits d'hydratation perturbateurs des cendres volantes de la biomasse quand ces cendres sont partiellement mélangées avec du ciment dans la fabrication du béton. Le processus de pré-mouillage de la cendre de boue de désencrage avant la fabrication du béton réduit les produits d'hydratation perturbateurs et par conséquent les propriétés mécaniques du béton sont améliorées. Les approches pour étudier la cendre de boue de désencrage dans ce projet sont : 1) caractérisation de cette cendre volante régulière et pré-humidifiée, 2) l'étude de la performance du mortier et du béton incorporant cette cendre volante régulière et pré-humidifiée. Le RSA est un nouveau sous-produit industriel. La haute teneur en silice amorphe en RSA est un excellent potentiel en tant que matériau cimentaire dans le béton. Dans ce projet, l'évaluation des RSA comme matériaux cimentaires alternatifs compose trois étapes. Tout d'abord, la caractérisation par la détermination des propriétés minéralogiques, physiques et chimiques des RSA, ensuite, l'optimisation du taux de remplacement du ciment par le RSA dans le mortier, et enfin l'évaluation du RSA en remplacement partiel du ciment dans différents types de béton dans le système binaire et ternaire. Cette étude a révélé que le béton de haute performance (BHP) incorporant le RSA a montré des propriétés mécaniques et la durabilité, similaire du contrôle. Le RSA a amélioré les propriétés des mécaniques et la durabilité du béton ordinaire (BO). Le béton autoplaçant (BAP) incorporant le RSA est stable, homogène et a montré de bonnes propriétés mécaniques et la durabilité. Le RSA avait une bonne synergie en combinaison de liant ternaire avec d'autres matériaux cimentaires supplémentaires. Cette étude a montré que le RSA peut être utilisé comme nouveaux matériaux cimentaires dans le béton.