Made available in DSpace on 2016-01-26T18:56:23Z (GMT). No. of bitstreams: 1 Dissertacao.pdf: 308272 bytes, checksum: 7df0ae05e2e184b04647e81dec8c55af (MD5) Previous issue date: 2010-08-10 / Expressive part of the peanut (Arachis hypogaea) in São Paulo State has cultivated for rotation in condemned areas of sugar cane that need to be reformed, and those areas frequently have presented low micronutrients levels and low basis saturation in soil. The objective of this work was to quantify the production and the yield components of the peanut crop fertilized with lime and gypsum applied in sowing combined with boron manure by leaf spray. The experiment was carried out from December 2007 to April 2008, on a dystroferric Hapludox, medium texture, in Guararapes, SP, Brazil. A randomized complete blocks design, with four replicates, and split plots, was used. The plots were composed by absence of Ca font (control), dolomite limestone with 0,5, 1 and 2 Mg ha-1 and gypsum with 0,5, 1 and 2 Mg ha-1, applied on sowing time of the peanut crop. The subplots were composed by levels boron with 0, 0,5, 1 and 2 kg ha-1 applied by leaf spray in initial flowering stage of the plants. The peanut crop presented expressive response to boron manuring, and the largest grains and pods productivities were obtain with 1 kg ha-1 of B. Fertilizations only Ca fonts applied in peanut sowing didn´t increase productivity and yield components. Combinations between Ca fonts applied in crop sowing and boron manuring by leaf spray favored the net yield of grains after peel off. / Grande parte do amendoim do Estado de São Paulo é cultivada em áreas de reforma de canavial, nas quais é comum o solo apresentar baixos teores de micronutrientes e de saturação por bases. O objetivo do trabalho foi avaliar a produtividade e rendimento do amendoim fertilizado com calcário e gesso na instalação da lavoura, combinados com adubação boratada foliar, em área de renovação de canavial. O experimento foi conduzido de dezembro de 2007 a abril de 2008 em um Latossolo vermelho distroférrico de textura média, em Guararapes-SP. O delineamento experimental foi em blocos completos e parcelas sub-divididas, em que nas parcelas foram a ausência de fonte de Ca na instalação da lavoura, 0,5, 1,0 e 2,0 t ha-1 de calcário dolomítico, e 0,5, 1,0 e 2,0 t ha-1 de gesso agrícola, e nas sub-parcelas 0, 0,5, 1 e 2 kg ha-1 de B foliar. O amendoim foi responsivo à adubação boratada, sendo as maiores produtividades de vagens e de grãos, assim como o máximo rendimento de grãos, alcançados com 1 kg ha-1 de B. A fertilização somente com fonte de Ca na semeadura do amendoim não incrementou a produção e rendimento de grãos. A combinação entre fontes de Ca na instalação da cultura e B foliar favorece o rendimento de grãos do amendoim após o descascamento.

Made available in DSpace on 2016-07-18T17:51:07Z (GMT). No. of bitstreams: 1 Dissertacao.pdf: 308272 bytes, checksum: 7df0ae05e2e184b04647e81dec8c55af (MD5) Previous issue date: 2010-08-10 / Expressive part of the peanut (Arachis hypogaea) in São Paulo State has cultivated for rotation in condemned areas of sugar cane that need to be reformed, and those areas frequently have presented low micronutrients levels and low basis saturation in soil. The objective of this work was to quantify the production and the yield components of the peanut crop fertilized with lime and gypsum applied in sowing combined with boron manure by leaf spray. The experiment was carried out from December 2007 to April 2008, on a dystroferric Hapludox, medium texture, in Guararapes, SP, Brazil. A randomized complete blocks design, with four replicates, and split plots, was used. The plots were composed by absence of Ca font (control), dolomite limestone with 0,5, 1 and 2 Mg ha-1 and gypsum with 0,5, 1 and 2 Mg ha-1, applied on sowing time of the peanut crop. The subplots were composed by levels boron with 0, 0,5, 1 and 2 kg ha-1 applied by leaf spray in initial flowering stage of the plants. The peanut crop presented expressive response to boron manuring, and the largest grains and pods productivities were obtain with 1 kg ha-1 of B. Fertilizations only Ca fonts applied in peanut sowing didn´t increase productivity and yield components. Combinations between Ca fonts applied in crop sowing and boron manuring by leaf spray favored the net yield of grains after peel off. / Grande parte do amendoim do Estado de São Paulo é cultivada em áreas de reforma de canavial, nas quais é comum o solo apresentar baixos teores de micronutrientes e de saturação por bases. O objetivo do trabalho foi avaliar a produtividade e rendimento do amendoim fertilizado com calcário e gesso na instalação da lavoura, combinados com adubação boratada foliar, em área de renovação de canavial. O experimento foi conduzido de dezembro de 2007 a abril de 2008 em um Latossolo vermelho distroférrico de textura média, em Guararapes-SP. O delineamento experimental foi em blocos completos e parcelas sub-divididas, em que nas parcelas foram a ausência de fonte de Ca na instalação da lavoura, 0,5, 1,0 e 2,0 t ha-1 de calcário dolomítico, e 0,5, 1,0 e 2,0 t ha-1 de gesso agrícola, e nas sub-parcelas 0, 0,5, 1 e 2 kg ha-1 de B foliar. O amendoim foi responsivo à adubação boratada, sendo as maiores produtividades de vagens e de grãos, assim como o máximo rendimento de grãos, alcançados com 1 kg ha-1 de B. A fertilização somente com fonte de Ca na semeadura do amendoim não incrementou a produção e rendimento de grãos. A combinação entre fontes de Ca na instalação da cultura e B foliar favorece o rendimento de grãos do amendoim após o descascamento.

Many endothelial cell (EC) functions depend on influx of extracellular Ca2+, which is triggered by a variety of mechanical and chemical signals. Here, we discuss possible pathways for this Ca2+ entry. The superfamily of cation channels derived from the "transient receptor potential" (TRP) channels is introduced. Several members of this family are expressed in ECs, and they provide pathways for Ca2+ entry. All TRP subfamilies may contribute to the Ca2+ entry channels or to the regulation of Ca2+ entry in EC. Members of Ca2+ entry channels in endothelium probably belong to the canonical TRP subfamily, TRPC. All TRPC1-6 have been discussed as Ca2+ entry channels that might be store-operated and/or receptor-operated. More importantly, knockout models of TRPC4 have proven that this channel is functionally involved in the regulation of endothelial-dependent vasorelaxation and in the control of EC barrier function. TRPC1 might be an important candidate for involvement of eodothelial growth factors. TRPC3 is unequivocally important for a sustained EC Ca2+ entry. ECs express different patterns of TRPCs, which may increase the variability of TRPC channel function by formation of different multiheteromers. Among the two other TRP subfamilies, TRPMV and TRPM, at least TRPV4 and TRPM4 are EC channels. TRPV4 is a Ca2+ entry channel that is activated by an increase in cell volume, which might be involved in mechano-sensing, by an increase in temperature, and perhaps by ligand-activation. TRPM4 is a nonselective cation channel, which is not Ca2+ permeable. It is probably modulated by NO and might be essential for regulating the inward driving force for Ca2+ entry. Possible modes of TRP channel regulation are described, involving (a) activation via the phospholipase (PL)Cβ and PLCγ pathways; (b) activation by lipids (diacylglycerol [DAG], arachidonic acid); (c) Ca2+ depletion of Ca2+ stores in the endoplasmic reticulum; (d) shear stress; and (e) radicals.

Urotensin-II (U-II), a peptide with multiple vascular effects, is detected in cholinergic neurons of the rat brainstem and spinal cord. Here, the effects of U-II on [Ca2+]i, was examined in dissociated rat spinal cord neurons by fura 2 microfluorimetry. The neurons investigated were choline acetyltransferase-positive and had morphological features of motoneurons. U-II induced [Ca2+]i, increases in these neurons with a threshold of 10-9 M, and a maximal effect at 10-6 M with an estimated EC50 of 6.2 × 10-9 M. The [Ca2+]i increase induced by U-II was mainly caused by Ca2+ influx from extracellular space, as the response was markedly attenuated in a Ca2+-free medium. Omega-conotoxin GVIA (10-7 M), a N-type Ca2+ channel blocker, largely inhibited these increases, whereas the P/Q Ca2+ channel blocker, omega-conotoxin GVIIC (10-7 M) and the L-type Ca2+ channel blocker, verapamil (10-5 M) had minimal effects. Down-regulation of protein kinase C by 4-α-phorbol 12-myristate 13-acetate (10-6 M) or enzyme inhibition using the specific inhibitor bisindolylmaleimide I (10-6 M) did not inhibit the observed effects. Similarly, inhibition of protein kinase G with KT5823 (10-6 M) or Rp-8-pCPT-cGMPS (3 × 10-5 M) did not modify U-II-induced [Ca2+]i increases. In contrast, protein kinase A inhibitors KT5720 (10-6 M) and Rp-cAMPS (3 × 10-5 M) reduced the response to 25 ± 3% and 42 ± 8%, respectively. Present results demonstrate that U-II modulates [Ca2+]i, in rat spinal cord neurons via protein kinase A cascade.

Recent studies show that angiotensin II (AngII) can act from within the cell, possibly via intracellular receptors pharmacologically different from typical plasma membrane AngII receptors. The role of this intracellular AngII (AngIIi) is unclear. Besides direct effects of AngIIi on cellular processes one could hypothesise a possible role of AngIIi in modulation of cellular responses induced after heterologous receptor stimulation. We therefore examined if AngIIi influences [Ca2+]i in A7r5 smooth muscle cells after serotonin (5HT) or UTP receptor stimulation. Application of AngIIi using liposomes, markedly inhibited 45Ca2+ influx after receptor stimulation with 5HT or UTP. This inhibition was reversible by intracellular administration of the AT1-antagonist losartan and not influenced by the AT2-antagonist PD123319. Similar results were obtained in single cell [Ca2+]i measurements, showing that AngIIi predominantly influences Ca2+ influx and not Ca2+ release via AT1-like receptors. It is concluded that AngIIi modulates signal transduction activated by heterologous receptor stimulation.

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Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.