990 resultados para TREE HEVEA-BRASILIENSIS


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Technological functional properties of native and acid-thinned pinhão (seeds of Araucária angustifolia, Brazilian pine) starches were evaluated and compared to those of native and acid-thinned corn starches. The starches were hydrolyzed (3.2 mol.L-1 HCl, 44 ºC, 6 hours) and evaluated before and after the hydrolysis reaction in terms of formation, melting point and thermo-reversibility of gel starches, retrogradation (in a 30-day period and measurements every three days), paste freezing and thawing stability (after six freezing and thawing cycles), swelling power, and solubility. The results of light transmittance (%) of pastes of native and acid-thinned pinhão starches was higher (lower tendency to retrogradation) than that obtained for corn starches after similar storage period. Native pinhão starch (NPS) presented lower syneresis than native corn starch (NCS) when submitted to freeze-thaw cycles. The acid hydrolysis increased the syneresis of the two native varieties under storage at 5 ºC and after freezing and thawing cycles. The solubility of NPS was lower than that of native corn starch at 25, 50, and 70 ºC. However, for the acid-thinned pinhão starch (APS), this property was significantly higher (p < 0.05) when compared to that of acid-thinned corn starch (ACS). From the results obtained, it can be said that the acid treatment was efficient in producing a potential fat substitute from pinhão starch variety, but this ability must be further investigated.

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Abstract The aim of this study was to assess the anti-quorum sensing activity of phenolic extracts from grumixama (Eugenia brasiliensis), also known as Brazilian cherry, in concentrations that did not interfere with bacterial growth. The pulp phenolic compounds were extracted by using solid phage extraction in a mini-collumn C18 and quantified by spectrophotometry. The anti-quorum sensing activity was evaluated by testing the inhibition of violacein production in Chromobacterium violaceum and by evaluating the swarming motility in Aeromonas hydrophila and Serratia marcescens, both phenotypes regulated by quorum sensing. The phenolic extract strongly inhibited the production of violacein in C. violaceum, reducing its production in comparison with a control with no extract. No inhibition of growth was observed at the concentrations tested for quorum sensing inhibition. Confirming the quorum sensing inhibition phenotype, the extract was also able to inhibit swarming motility in S. marcescens and in A. hydrophila, although in the later the effect was marginal. Overall, these results indicate that phenolic extract from E. brasiliensis presents quorum sensing inhibitory activity most likely due to the presence of fruit phenolics which have been implicated as quorum sensing inhibitors in Gram negative bacteria.

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O objetivo deste trabalho foi avaliar a germinação de sementes de cataia (Drimys brasiliensis) sob diferentes temperaturas e tempos de estratificação. As sementes foram submetidas ao método de estratificação em casa de vegetação, sem controle de temperatura, durante 30, 60 e 90 dias. Foram testados os substratos papel de filtro, areia, vermiculita e ágar a 1% e as temperaturas constantes de 17ºC, 25ºC e 30ºC, na presença de luz contínua e temperatura alternada de 20-30ºC, sendo 20ºC por 16 horas no escuro e 30ºC por 8 horas em presença de luz. O vigor foi avaliado por meio do índice de velocidade de germinação (I.V.G.). As sementes apresentaram grau de umidade inicial de 7% (base úmida). Após 30, 60, 90 dias de estratificação o grau de umidade passou para 11,3%, 27,7% e 46,2%, respectivamente. Os valores da porcentagem de germinação foram de 67% e 52% nos tratamentos com 30 e 60 dias de estratificação, respectivamente, obtidos na temperatura de 17ºC. Os valores de germinação obtidos com 30 dias de estratificação foram 68% para os substratos ágar, areia, e papel de filtro e 61% para o substrato vermiculita. No tratamento com 60 dias de estratificação, os valores de porcentagem de germinação foram 56%, 58% e 54% nos substratos ágar, areia e papel de filtro, respectivamente, não diferindo estatisticamente entre si. As sementes mais vigorosas foram as estratificadas durante 60 dias e colocadas para germinar nos substratos ágar, areia e papel de filtro, na temperatura de 17ºC, onde foram obtidos os valores 0,55, 0,61 e 0,65 para I.V.G., respectivamente. As sementes apresentam dormência por imaturidade embrionária e a estratificação em areia durante 60 dias é um método eficiente para superar a dormência das sementes de cataia. Os maiores valores de velocidade e percentagem de germinação em sementes de cataia são obtidos na temperatura constante de 17ºC com o uso dos substratos ágar, areia e papel de filtro.

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Este trabalho teve como objetivo caracterizar morfologicamente as estruturas externas e internas dos frutos e das sementes de cataia (Drimys brasiliensis Miers.). Para a descrição dos frutos foram observados detalhes externos e internos do pericarpo, referentes à textura, consistência, pilosidade, brilho, forma, número de sementes por fruto e deiscência. Para as sementes foram analisadas as seguintes variáveis externas: dimensões, cor, textura, consistência, forma, posição do hilo e da micrópila. Para as características internas, verificou-se a presença ou ausência de endosperma, o tipo, a forma, a cor, o desenvolvimento embrionário e posição dos cotilédones, do eixo-hipocótilo-radícula e da plúmula. Durante o desenvolvimento embrionário, foram encontrados embriões que variaram de acordo com a diferenciação celular, evidenciando seus aspectos morfológicos, nos estágios de coração, torpedo e maduro. Os frutos de D. brasiliensis são múltiplos, livres, constituídos por cinco frutíolos, bagas, indeiscentes e polispérmicos. As sementes são reniformes e têm grande quantidade de endosperma, e apresentam dormência por imaturidade embrionária.

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Há grande demanda por pesquisas com espécies arbóreas nativas do Brasil, principalmente quanto à qualidade fisiológica de suas sementes. Visando avaliar o grau de tolerância à dessecação e a capacidade de armazenamento das sementes de grumixameira (Eugenia brasiliensis), frutos maduros foram coletados em Mogi-Guaçu, SP. Após a colheita, as sementes foram extraídas, lavadas e secas a 36ºC, reduzindo seu teor de água inicial de 48,9% (base úmida) para até 23,6% (última secagem), totalizando cinco níveis de secagem. Amostras de sementes de cada nível de secagem foram armazenadas em sacos plásticos, a 7ºC, até 270 dias. Os resultados mostraram que a redução do teor de água para valores inferiores a 43,1% prejudicou tanto a germinabilidade quanto a capacidade de conservação em armazenamento das sementes. Sementes com 48,9% de água apresentaram 60% de germinação após 180 dias de armazenamento e 19% após 270 dias, quando mantidas em sacos plásticos e em câmara fria. Concluiu-se que sementes de E. brasiliensis podem ser armazenadas por 180 dias a 7ºC e são sensíveis à secagem a 36ºC.

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Schinopsis brasiliensis Engl. é uma espécie nativa da catinga de grande potencial econômico. A germinação das suas sementes compreende uma série de processos, que começa com a embebição de água e termina com a emergência da plântula através do tegumento. Pouco se conhece, no entanto, sobre a velocidade de embebição e metabolismo germinativo desta espécie. O objetivo deste trabalho foi obter a curva de embebição e avaliar as alterações bioquímicas que ocorrem nas sementes de baraúna durante a germinação. As sementes foram separadas em três repetições de 10 sementes e submetidas à embebição por até 200 horas. Foram avaliados o volume de água embebida pelas sementes, os teores de açucarar solúveis totais (AST), açucares redutores (AR), amido e proteínas de reserva. Pela curva de embebição das sementes de baraúna pode ser observado um modelo trifásico, onde a fase (F) I é completada em 48h e a FIII tem inicio após 152h de embebição, com protrusão da raiz. Os teores de AR e AST nas sementes aumentam durante a embebição, enquanto os teores de amido diminuíram após a FII. Os teores de albuminas, globulinas e prolaminas permaneceram constantes durante as FI e FII e diminuíram após a protrusão da raiz e os teores de glutelinas foram praticamente nulos durante a germinação de sementes de baraúna.

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Changes in the abundance of top predators have brought about notable, cascading effects in ecosystems around the world. In this thesis, I examined several potential trophic cascades in boreal ecosystems, and their separate interspecific interactions. The main aim of the thesis was to investigate whether predators in the boreal forests have direct or indirect cascading effects on the lower trophic levels. First, I compared the browsing effects of different mammalian herbivores by excluding varying combinations of voles, hares and cervids from accessing the seedlings of silver birch (Betula pendula), Scots pine (Pinus sylvestris) and Norway spruce (Picea abies). Additionally, I studied the effect of simulated predation risk on vole browsing by using auditory cues of owls. Moving upwards on the trophic levels, I examined the intraguild interactions between the golden eagle (Aquila chrysaetos), and its mesopredator prey, the red fox (Vulpes vulpes) and the pine marten (Martes martes). To look at an entire potential trophic cascade, I further studied the combined impacts of eagles and mesopredators on the black grouse (Tetrao tetrix) and the hazel grouse (Tetrastes bonasia), predicting that the shared forest grouse prey would benefit from eagle presence. From the tree species studied, birch appears to be the most palatable one for the mammalian herbivores. I observed growth reductions in the presences of cervids and low survival associated with hares and voles, which suggests that they all weaken regeneration in birch stands. Furthermore, the simulated owl predation risk appeared to reduce vole browsing on birches in late summer, although the preferred grass forage is then old and less palatable. Browsing by voles and hares had a negative effect on the condition and survival of Scots pine, but in contrast, the impact of mammalian herbivores on spruce was found to be small, at least when more preferred food is available. I observed that the presence of golden eagles had a negative effect on the abundance of adult black grouse but a positive, protective effect on the proportion of juveniles in both black grouse and hazel grouse. Yet, this positive effect was not dependent on the abundance foxes or martens, nor did eagles seem to effectively decrease the abundance of these mesopredators. Conversely, the protection effect on grouse could arise from fear effects and also be mediated by other mesopredators. The results of this thesis provide important new information about trophic interactions in the boreal food webs. They highlight how different groups of mammalian herbivores vary in their effects on the growth and condition of different tree seedlings. Lowered cervid abundances could improve birch regeneration, which indirectly supports the idea that the key predators of cervids could cause cascading effects also in Fennoscandian forests. Owls seem to reduce vole browsing through an intimidation effect, which is a novel result of the cascading effects of owl vocalisation and could even have applications for protecting birch seedlings. In the third cascade examined in this thesis, I found the golden eagle to have a protective effect on the reproducing forest grouse, but it remains unclear through which smaller predators this effect is mediated. Overall, the results of this thesis further support the idea that there are cascading effects in the forests of Northern Europe, and that they are triggered by both direct and non‐lethal effects of predation.

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The fall of 2013 could be characterized as a crossroad in the geopolitics of Eastern Europe, namely Ukraine. Two rivalry geopolitical projects have been developing throughout the post-Cold War years, and it seems that they reached a collision point in Ukraine; a country whose authorities have been for long switching sides between the European Union and the Russian Federation in their foreign policy commitments. The refusal/postponing to sign the Association Agreement with Brussels, an expected event by a large category of the Ukrainian society, by Yanukovich’s government led to the outset of the latter; and brought a pro-Western, anti-Russian government in Kyiv. It seems that Ukraine, after those events, has embarked definitively on the path of integration into the West (European Union and possibly NATO). The Russian Federation, who has been throughout Putin’s years engaged into the re-integration of post-Soviet space, reacted to these developments in an assertive manner by violating borders, agreements and the territorial integrity of Ukraine. Thus, the incorporation of the Crimea into the Russian Federation is the first in its kind in the post-Soviet space, despite the existence of various other conflicts that broke out in the region after the Soviet Union broke up. I will investigate in this thesis the nature of what will be labelled, in this work, the Crimean issue. I argue that the incorporation of the Crimean peninsula into the Russian Federation marks a new era in Russian geopolitical thinking that shapes, to a far extent, Russian foreign policy. Discourse analysis will be the methodological basis for this study, with a special focus on Michel Foucault’s Archaeology of Knowledge. The innovation that this research brings is the fact that it discusses Russian geopolitical discourse within the scope of Foucault’s ‘discursive tree’, with a reference to the Crimean issue. A wide range of primary sources will be consulted in this study such as presidential addresses to the Federal Assembly (2000-2014), Foreign Policy Concepts of the Russian Federation (2000, 2008), Russian maritime doctrines, as wells as Dugin’s Osnovy Geopolitiki (Foundations of Geopolitics), Mahan’s (The Influence of Sea Power Upon History, 1660–1783) and other Eurasianism related literature.

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Fokuserande händelser är plötsliga, ovanliga och för med sig negativa konsekvenser för ett stort antal människor. Det handlar om det vi i vardagligt tal kallar kriser och katastrofer. En intensiv medierapportering i kombination med oroade medborgare gör att kriser och katastrofer är viktiga samhällspåfrestningar som beslutsfattare måste hantera. Syftet med avhandlingen är att öka förståelsen för hur fokuserande händelser påverkar samhälleliga processer. Avhandlingens två övergripande forskningsfrågor tar fasta på jämförelsen av olika typer av fokuserande händelser. För det första, skillnader i hur naturkatastrofer och katastrofer som tillkommit genom mänskligt handlade påverkar samhället, och för det andra, hur händelser med olika stark fokuseringskraft påverkar samhället. Medborgarreaktioner studeras i en experimentell laboratoriestudie, den mediala rapporteringen analyseras genom kvantitativ innehållsanalys av texter och bilder, och på den parlamentariska arenan analyseras riksdagsdebatten genom kvantitativ innehållsanalys. De temaområden som identifieras i den teoretiska referensramen ligger till grund för analysen och tar fasta på de känslor som händelsen ger upphov till, hur händelsen kontextualiseras (framing), skuldbeläggning samt möjliga lösningar som förs fram. Resultatet från studierna visar att skillnader mellan olika typer av händelser syns tydligast hos medborgare, uttryckt genom starkare emotionella reaktioner för händelser med stark fokusering, och på den mediala arenan, genom mer utrymme för dessa händelser. Då kriser och katastrofer med olika stark fokuseringskraft når riksdagen får de däremot ett relativt likadant mottagande. I jämförelsen mellan naturkatastrofer och människoskapade händelser visar resultaten att naturkatastrofer ofta diskuteras som specifika händelser, medan människoskapade händelser placeras i en bredare samhällelig kontext och diskuteras under längre tid. Avhandlingen bidrar till diskussionen om hur våra känslor och vår kognition samspelar i krissituationer. De omedvetna signaler som vår kropp ger oss gällande hur vi ska reagera på en farlig situation kan påverka om vi är rädda, oroliga eller till och med positivt inställda. I ljuset av de tre studierna är det tydligt att de emotionella reaktionerna minskar ju högre upp i den politiska processen vi kommer. Trots att medborgare och medier reagerar starkt är de emotionella reaktionerna på den politiska arenan relativt milda och skuldbeläggningen näst intill icke-existerande.

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Changes in the configuration of a tree stern result insignificant differences in its total volume and in the proportion of that volume that is merchantable timber. Tree allometry, as represented by stem-fo~, is the result of the vertical force of gravity and the horizontal force of wind. The effect of wind force is demonstrated in the relationship between stem-form, standclosure and site-conditions. An increase in wind force on the individual tree due to a decrease in stand density should produce a more tapered tree. The density of the stand is determined by the conditions that the trees are growing under. The ability of the tree to respond to increased wind force may also be a function of these conditions . This stem-form/stand-closure/site-conditions relationship was examined using a pre-existing database from westcentral Alberta. This database consisted of environmental, vegetation, soils and timber data covering a wide range of sites. There were 653 sample trees with 82 variables that formed the basis of the analysis. There were eight tree species consisting of Pinus contorta, Picea mariana, Picea engelmannii x glauca, Abies lasiocarpa, Larix laricina, Populus tremuloides, Betula papyrifera and Populus balsamifera plus a comprehensive all-species data set. As the actual conformation of the stern is very individual, stem-fo~was represented by the diameter at breast height to total height r~tio. The four stand-closure variables, crown closure, total basal area, total volume and total number of stems were reduced to total basal area and total number of stems utilizing a bivariate correlation matrix by species. Site-conditions were subdivided into macro, meso and micro variables and reduced in number 3 using cross-tabulations, bivariate correlation and principal components analysis as screening tools. The stem-fo~/stand-closure relationship was examined using bivariate correlation coefficients for stem-fo~ with total number of stems and stem-fo~ with total basal area. The stem-fo~/site-conditions and the stand-closure/site- conditions relationships were examined using multiple correlation coefficients. The stem-form/stand-closure/site-conditions relationship was examined using multiple correlation coefficients in separate analyses for both total number of stems and total basal area. An increase in stand-closure produced a decrease in stem-form for both total number of stems and total basal area for most species. There was a significant relationship between stem-form and site-conditions and between stand-closure and site-conditions for both total number of stems and total basal area for most species. There was a significant relationship between the stemform and site-conditions, including the stand-closure, for most species; total number of stems was involved independently of the site-conditions in the prediction of stem-form and total basal area was not. Larix laricina and Betula papyrifera were the exceptions to the trends observed with most species. The influence of both stand-closure (total number of stems in particular) and site-conditions (elevation in particular) suggest that forest management practices should include these- ecological parameters in determining appropriate restocking levels.

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Joyce Chapman posing by an orange tree, West Covina, California, 1998.

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Excavating a fossilized tree, which was later placed in front of Hashinger Hall, Chapman University, 346 N. Center Street, Orange, California. The late Dr. Edward H. Hashinger, former trustee and past chairman of the board is the man whose name has graced the walls of this building since 1969. The Hashinger Science Center (3 floors, 65,364 sq.ft.) houses all science departments including biology, natural and applied sciences, environmental and chemical sciences, food science and nutrition, kinesiology and physical therapy.

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Placing a fossilized tree in front of Hashinger Hall, Chapman College, 346 N. Center Street, Orange, California. The late Dr. Edward H. Hashinger, former trustee and past chairman of the board is the man whose name has graced the walls of this building since 1969. The Hashinger Science Center (3 floors, 65,364 sq.ft.) houses all science departments including biology, natural and applied sciences, environmental and chemical sciences, food science and nutrition, kinesiology and physical therapy.

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A report done by Donald Ziraldo on the topic of Tree Fruit, specifically peach, in nurseries. The report was likely done while he was a student of the University of Guelph in the 1970s.

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A photograph of Percy Band wearing a suit as he stands in front of a large tree. A house can be seen just behind the tree.