Dark Substance
Mostrando 1-12 de 16 artigos, teses e dissertações.
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1. Acelaração do universo e criação gravitacional de matéria escura fria: novos modelos e testes observacionais
Recent astronomical observations (involving supernovae type Ia, cosmic background radiation anisotropy and galaxy clusters probes) have provided strong evidence that the observed universe is described by an accelerating, flat model whose space-time properties can be represented by the FriedmannRobertsonWalker (FRW) metric. However, the nature of the substanc
Publicado em: 2008
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2. Efeitos das inomogeneidades da matéria em Cosmologias Aceleradas
Os recentes avanços observacionais da Astronomia e um arcabouço teórico cada vez mais consistente, transformaram a Cosmologia numa das mais excitantes áreas da ciência contemporânea. Nesta tese, modelos homogêneos e inomogêneos contendo matéria escura e diferentes tipos de energia escura são confrontados com dados observacionais recentes. Inicialme
Publicado em: 2007
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3. Evaluation of drying period and quality of image of radiographs submitted to immersion in ethyl alcohol at different concentrations / Avaliação do tempo de secagem e da qualidade da imagem de radiografias submetidas a banho em alcool etilico em diferentes concentraçãoes
This study evaluated the action of ethyl alcohol at concentrations of 46ºGL, 70ºGL and 92ºGL as an accelerator of drying of dental radiographs, with a view to reduce the time required for processing. Also, it was observed whether this product might cause alterations in the density, sensitometric properties and quality of these radiographs after a 6- month
Publicado em: 2005
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4. Utilização de dejetos líquidos de suínos na adubação da cana-de-açúcar / Sugarcane fertilization with liquid dejections of swines
The present research was conducted at Fazenda Porto Alfenas-MG with purpose of determining the effect of doses of liquid swine dejections on sugarcane productivity and concentration of nutrient in the soil Two types of fertilization were tested in a second-cut sugarcane plantation variety SP 81-3250 in dark red dystrophic latosoil (LVEd): (1) liquid dejectio
Publicado em: 2005
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5. Efeito alelopÃtico do extrato aquoso de sementes de Cumaru (Amburana cearensis S.) sobre a germinaÃÃo de sementes, desenvolvimento e crescimento de plÃntulas de alface, picÃo-preto e carrapicho. / AlelopÃtico effect of the watery extract of seeds of Cumaru (Amburana cearensis S.) on the germination of seeds, development and growth of plÃntulas of lettuce, picÃo-preto (Bidens pilosa L.) and carrapicho.
The objective of the present work was to evaluate methods (maceration, decoccion and infusion) and times (30, 60 and 120 min. ) of extraction, besides the substances: fractions chloroform and acetate, and pure coumarin, in different concentrations, of the aqueous extract of cumaru seeds (Amburana cearensis S. ) on the germination, the development and the gro
Publicado em: 2004
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6. Glutamate and substance P coexist in primary afferent terminals in the superficial laminae of spinal cord.
By light microscopic immunocytochemistry it has been previously shown that approximately equal to 70% of the neurons in rat dorsal root ganglia are labeled with an antiserum for glutamate conjugated to hemocyanin; the smaller among these neurons are also positive for substance P. By using a postembedding ImmunoGold method and electron microscopy, it is shown
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7. INDUCTION OF FERN SPORE GERMINATION*
Light-induced germination of Anemia spores can be inhibited by AMO-1618, a selective inhibitor of gibberellin biosynthesis. The inhibitor has no effect on gibberellin-induced dark germination and its inhibition of light-induced germination can be reversed by supplying gibberellin. Barley-endosperm bioassay of concentrates of medium in which spores are imbibe
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8. Participation of Long-Day Inhibition in Flowering of Xanthium strumarium L. 1
Two basic experiments defined a long-day inhibitory effect on Xanthium flowering: the basal half of a single leaf on long day inhibits response of the tip half to a short day; and a long-day leaf inhibits response of a short-day leaf, providing it is between the short-day leaf and a receptive bud (whether above or below the short-day leaf). Five hypotheses w
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9. Communication between the Maternal Testa and the Embryo and/or Endosperm Affect Testa Attributes in Tomato1[w]
Two tomato (Lycopersicon esculentum) mutants with dark testae displaying poor germination rate and percentage on both water and 100 μm gibberellin4 + 7 were recovered. The mutants were allelic (black seed1-1; bks1-1 and bks1-2), inherited in Mendelian fashion as a recessive gene residing on chromosome 11. They are not allelic to bs (brown seed) -1, -2, or -
The American Society for Plant Biologists.
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10. Local effects of bleaching in retinal rods of the toad.
1. Suction electrode recordings were used to study the recovery of responsiveness in single toad rods after bleaching a small fraction (less than 5%) of the rhodopsin. 2. After a spatially uniform bleach that initially abolished the dark current over the entire length of the outer segment, the more proximal regions recovered faster than the more distal regio
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11. Effects of Germination-promoting Substances Given in Conjunction with Red Light on the Phytochrome-mediated Germination of Dormant Lettuce Seeds (Lactuca sativa L.)
Ethylene or thiourea can substitute for gibberellic acid but not for red light in breaking the secondary dormancy induced by extended dark storage of fully hydrated lettuce seeds (Lactuca sativa cv. Grand Rapids). After 10 days of storage, ethylene, thiourea, or gibberellic acid applied either separately or in any combination in conjunction with red light in
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12. Effect of the Hypocotyl Hook on Chlorophyll Accumulation in Excised Cotyledons of Cucumis sativus L
Hypocotyl hooks have been shown to influence greening in excised cucumber (Cucumis sativus) cotyledons. The properties of the lag phase are greatly affected by the presence or absence of the hook tissue. A 45-second light pretreatment followed by 4 hours of darkness is sufficient to remove the lag phase from cotyledons with hooks, while hookless cotyledons r