995 resultados para Propagação de planta
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Mode of access: Internet.
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Bibliography: p. [205]-206.
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We report the cloning and characterization in tobacco and Arabidopsis of a Vigna radiata L. (mung bean) promoter that controls the expression of VR-ACS1, an auxin-inducible ACC synthase gene. The VR-ACS1 promoter exhibits a very unusual behavior when studied in plants different from its original host, mung bean. GUS and luciferase in situ assays of transgenic plants containing VR-ACS1 promoter fusions show strong constitutive reporter gene expression throughout tobacco and Arabidopsis development. In vitro quantitative analyses show that transgenic plants harboring VR-ACS1 promoter-reporter constructs have on average 4-6 fold higher protein and activity levels of both reporter genes than plants transformed with comparable CaMV 35S promoter fusions. Similar transcript levels are present in VR-ACS1 and CaMV 35S promoter lines, suggesting that the high levels of gene product observed for the VR-ACS1 promoter are the combined result of transcriptional and translational activation. All tested deletion constructs retaining the core promoter region can drive strong constitutive promoter activity in transgenic plants. This is in contrast to mung bean, where expression of the native VR-ACS1 gene is almost undetectable in plants grown under normal conditions, but is rapidly and highly induced by a variety of stimuli. The constitutive behavior of the VR-ACS1 promoter in heterologous hosts is surprising, suggesting that the control mechanisms active in mung bean are impaired in tobacco and Arabidopsis. The 'aberrant' behavior of the VR-ACS1 promoter is further emphasized by its failure to respond to auxin and cycloheximide in heterologous hosts. VR-ACS1 promoter regulatory mechanisms seem to be different from all previously characterized auxin-inducible promoters.
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We investigated controls on the water chemistry of a South Ecuadorian cloud forest catchment which is partly pristine, and partly converted to extensive pasture. From April 2007 to May 2008 water samples were taken weekly to biweekly at nine different subcatchments, and were screened for differences in electric conductivity, pH, anion, as well as element composition. A principal component analysis was conducted to reduce dimensionality of the data set and define major factors explaining variation in the data. Three main factors were isolated by a subset of 10 elements (Ca2+, Ce, Gd, K+, Mg2+, Na+, Nd, Rb, Sr, Y), explaining around 90% of the data variation. Land-use was the major factor controlling and changing water chemistry of the subcatchments. A second factor was associated with the concentration of rare earth elements in water, presumably highlighting other anthropogenic influences such as gravel excavation or road construction. Around 12% of the variation was explained by the third component, which was defined by the occurrence of Rb and K and represents the influence of vegetation dynamics on element accumulation and wash-out. Comparison of base- and fast flow concentrations led to the assumption that a significant portion of soil water from around 30 cm depth contributes to storm flow, as revealed by increased rare earth element concentrations in fast flow samples. Our findings demonstrate the utility of multi-tracer principal component analysis to study tropical headwater streams, and emphasize the need for effective land management in cloud forest catchments.
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To improve our knowledge of the influence of land-use on solute behaviour and export rates in neotropical montane catchments we investigated total organic carbon (TOC), Ca, Mg, Na, K, NO3 and SO4 concentrations during April 2007-May 2008 at different flow conditions and over time in six forested and pasture-dominated headwaters (0.7-76 km2) in Ecuador. NO3 and SO4 concentrations decreased during the study period, with a continual decrease in NO3 and an abrupt decrease in February 2008 for SO4. We attribute this to changing weather regimes connected to a weakening La Niña event. Stream Na concentration decreased in all catchments, and Mg and Ca concentration decreased in all but the forested catchments during storm flow. Under all land-uses TOC increased at high flows. The differences in solute behaviour during storm flow might be attributed to largely shallow subsurface and surface flow paths in pasture streams on the one hand, and a predominant origin of storm flow from the organic layer in the forested streams on the other hand. Nutrient export rates in the forested streams were comparable to the values found in literature for tropical streams. They amounted to 6-8 kg/ha/y for Ca, 7-8 kg/ha/y for K, 4-5 kg/ha/y for Mg, 11-14 kg/ha/y for Na, 19-22 kg/ha/y for NO3 (i.e. 4.3-5.0 kg/ha/y NO3-N) and 17 kg/ha/y for SO4. Our data contradict the assumption that nutrient export increases with the loss of forest cover. For NO3 we observed a positive correlation of export value and percentage forest cover.
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A major and growing problems faced by modern society is the high production of waste and related effects they produce, such as environmental degradation and pollution of various ecosystems, with direct effects on quality of life. The thermal treatment technologies have been widely used in the treatment of these wastes and thermal plasma is gaining importance in processing blanketing. This work is focused on developing an optimized system of supervision and control applied to a processing plant and petrochemical waste effluents using thermal plasma. The system is basically composed of a inductive plasma torch reactors washing system / exhaust gases and RF power used to generate plasma. The process of supervision and control of the plant is of paramount importance in the development of the ultimate goal. For this reason, various subsidies were created in the search for greater efficiency in the process, generating events, graphics / distribution and storage of data for each subsystem of the plant, process execution, control and 3D visualization of each subsystem of the plant between others. A communication platform between the virtual 3D plant architecture and a real control structure (hardware) was created. The goal is to use the concepts of mixed reality and develop strategies for different types of controls that allow manipulating 3D plant without restrictions and schedules, optimize the actual process. Studies have shown that one of the best ways to implement the control of generation inductively coupled plasma techniques is to use intelligent control, both for their efficiency in the results is low for its implementation, without requiring a specific model. The control strategy using Fuzzy Logic (Fuzzy-PI) was developed and implemented, and the results showed satisfactory condition on response time and viability
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This study focused object a steam generation system, steam distribution and condensate return a textile plant located in Rio Grande do Norte. The work was based on the following objectives: Knowing the use of saturated water vapor in the dyeing and finishing processes in a textile plant; To study the various aspects of a steam distribution system to identify the ways in which energy losses occur; Obtain quantitative information of the main loss in steam generation system and steam distribution and to measure the losses, water and steam system; Using the flash steam as a means of cost reduction. For it was made use of the calculation of financial gains made in their respective improvements. As a database for the development of working registers are used in industrial processes, data from utility systems, laboratory data analysis and on-line analyzers, covering the period 2013. Using the principles set conservation laws mass and energy, those data showed that the loss of water and energy in the steam system are significant and that the environmental and economic gains to be obtained with improvement actions are quite significant. Based on the data and results suggest that future studies deem the continuity approach to steam generation systems, distribution and mainly condensate return.
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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.
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Compared to conventional composites, polymer matrix nanocomposites typically exhibit enhanced properties at a significantly lower filler volume fraction. Studies published in the literature indicate t hat the addition of nanosilicate s can increase the resistance to flame propagation in polymers. In this work, a treatment of montmorillonite (MMT) nano clay and the effect of its ad dition o n flame propagation characteristics of vinyl ester were studied. The resea rch was conducted in two stages. The first stage focused on the purification and activation of the MMT clay collected from a natural deposit to improve compatibility with the polymer matrix . Clay modification with sodium acetate was also studied to improve particle dispersion in the polymer. The second step was focused on the effect of the addition of the treated clay on nanocomposites ’ properties. Nanocomposites with clay con tents of 1, 2, 4 wt. % were processed. T he techniques for the characterization of the clay included X - ray fluorescence (XRF), X - r ay d iffraction (XRD), thermogravimetric a nalysis (TGA), d ifferential scanning c alorimetry (DSC) , s urface area (BET) and Fourier transform infrared spectroscopy (FTIR). For t he characterization of the nanocomposites , the techniques used were thermogravimetric a nalysis (TGA) , differential scanning c alorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) , scanning electron mi croscopy (SEM), transmission electron m icroscopy (TEM), and the determination of tensile strength, modulus of elasticity and resistance to flame propagation. According to the results, the purification and activation treatment with freeze - drying used in thi s work for the montmorillonite clay was efficient to promote compatibility and dispersion in the polymer matrix as evidenced by the characterization of the nanocomposite s . It was also observed that the clay modifica tion using sodium acetate did not produce any significant effect to improve compatibilization of the clay with the polymer. The addition of the treated MMT resulted in a reduction of up to 53% in the polymer flame propagation speed and did not affect the mechanical tensile strength and modulus o f elas ticity of the polymer, indicating compatibility between the clay and polymer. The effectiveness in reducing flame propagation speed peaked for nanocomposites with 2 wt. % clay, indicating that this is the optimum clay concentration for this property. T he clay treatment used in this work enables the production of vinylester matrix nanocomposites with flame - retardancy properties .
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Agriculture is an essential activity to the human development, the tendency is that their need to increase according to the increase in world population. It is very important to take the maximum performance that is possible of each land without degrading it, a frequently monitoring is essential for the best performance. The purpose of this work is, nondestructively, to monitor the surface electrical conductivity of the soil in a demarcated area, as on a plantation, using low frequency radio waves. The conductivity is directly linked to the amount of water in the area and nutrients, therefore a periodic or even permanent monitoring increases significantly the efficient of the use of the soil. They will be used long-wave radio transmission or medium whose main characteristic to spread over the surface of the earth. It is possible to choose an AM radio with location, frequency and power of the transmission known or generate the signal. The studied method computes the conductivity of the ground in a straight line between two measured points, so it can be used in smaller or larger size fields. Measurements were carried out using an electromagnetic field strength analyzer. The data obtained in the measurements are processed by a numerical calculation program, in our case Matlab. It is concluded that the recommendations of the ITU (International Telecommunication Union) on the conductivity of soil in Brazil is far from reality, on some routes the recommendations indicate the use of the electrical conductivity of the soil 1 mS/m, while the measurements was found 19 mS/m. With the method described a precision farmer, once initial research for about a year, can monitor the humidity and salinity of the land, with the ability to predict the area and the most suitable time for irrigation and fertilization, making management more efficient and less expensive, while optimizing water use, natural resource increasingly precious.
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La berenjena (Solanum melongena L.) es una planta solanácea de múltiples variedades, cuyos ancestros salvajes se sitúan en Indochina y el este de África. Su cultivo fue muy temprano en zonas de China e India. Aun así, no se extendió al Occidente antiguo ni apenas se conoció, de ahí su ausencia en los textos clásicos de botánica y farmacología. Fueron los árabes quienes llevaron el cultivo de la planta por el Norte de África y Al-Andalus, de donde pasó ya a Europa. Los primeros testimonios occidentales de la berenjena aparecen en traducciones latinas de textos árabes, para incorporarse luego a la literatura farmacológica medieval y, más tarde ya, a la del Renacimiento, que empezó a tratar de ella por su posible parecido con una especie de mandrágora. Pese a que se le reconocían algunas virtudes medicinales, siempre se la tuvo bajo sospecha por ser de sabor poco agradable, indigesta y causante de algunas afecciones. Solo los botánicos de finales del Renacimiento describirían la planta y sus variedades con criterios más «científicos» y botánicos, ya sin apenas intereses farmacológicos.