40 resultados para 31-300

em Brock University, Canada


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Growth stimulation of Avena coleoptile tissue by indoleacetic acid (IAA) and fusicoccin (FC) was compared by measuring both their influence on RNA and protein synthesis during IAA or FC stimulated growth. FC stimulated growth more than IAA during the initial four hour exposure, after which the growth rate gradually declined to the control rate. FC, but not IAA, increased the uptake of 3H-Ieucine into tissue and the specific radioactivity of extracted protein. Cycloheximide inhibited the incorporation of 3H-Ieucine into protein by approximately 60% to 70% in all cases. In the presence of cycloheximide 3H-radioactivity accumulated in FC-treated tissue, whereas IAA did not seem to influence 3H-accumulation. These results suggest that FC stimulated leucine uptake into the tissue and that increased specific activity of coleoptile protein is due to increased leucine uptake, not an increased rate of protein synthesis. There was no measurable influence of IAA and/or FC on RNA and protein synthesis during the initial hours of a growth stimulation. Inhibitors of RNA and protein synthesis, actinomycin D and cycloheximide, respectively, severely inhibited IAA enhanced growth but only partially inhibited FC stimulated growth. The data are consistent with suggestions that a rapidly turning over protein participates in IAA stimulated growth, and that a continual synthesis of RNA and proteins is an absolute requirement for a long term growth response to IAA. On the contrary, FC-stimulated growth exhibited less dependency on the transcription and translation processes. The data are consistent with proposals suggesting different sites of action for FC and IAA stimulated growth. l?hen compared to CO2-free air, CO2 at 300 ppm had no significant influence on coleoptile growth and protein synthesis in the presence or absence of lAA or FC. Also, I mM malate, pH 6.0 did not influence growth of coleoptiles in the presence or absence of lAA. This result was obtained despite reports indicating that 300 ppm CO2 or I mM malate stimulates growth and protein synthesis. This lack of difference between CO2-treated and untreated tissue could indicate either that the interstitial space CO2 concentration is not actually different in the two treatments due to significant endogenous respiratory CO2 or else the data would suggest a very loose coupling between dark CO2 fixation and growth. IAA stimulated the in vivo fixation of 14c-bicarbonate (NaHI4c03) by about 25% and the addition of cycloheximide caused an inhibition of bicarbonate fixation within 30 min. Cycloheximide has also been reported to inhibit IAA-stimulated H+ excretion. These data are consistent with the acid growth theory and suggest that lAA stimulated growth involves dark CO2 fixation. The roles of dark CO2 fixation in lAA-stimulated growth are discussed.

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Order parameter profiles extracted from the NMR spectra of model membranes are a valuable source of information about their structure and molecular motions. To al1alyze powder spectra the de-Pake-ing (numerical deconvolution) ~echnique can be used, but it assumes a random (spherical) dist.ribution of orientations in the sample. Multilamellar vesicles are known to deform and orient in the strong magnetic fields of NMR magnets, producing non-spherical orientation distributions. A recently developed technique for simultaneously extracting the anisotropies of the system as well as the orientation distributions is applied to the analysis of partially magnetically oriented 31p NMR spectra of phospholipids. A mixture of synthetic lipids, POPE and POPG, is analyzed to measure distortion of multilamellar vesicles in a magnetic field. In the analysis three models describing the shape of the distorted vesicles are examined. Ellipsoids of rotation with a semiaxis ratio of about 1.14 are found to provide a good approximation of the shape of the distorted vesicles. This is in reasonable agreement with published experimental work. All three models yield clearly non-spherical orientational distributions, as well as a precise measure of the anisotropy of the chemical shift. Noise in the experimental data prevented the analysis from concluding which of the three models is the best approximation. A discretization scheme for finding stability in the algorithm is outlined

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The Military Monitor was a weekly periodical that was published every Monday. The first issue was printed for August 17, 1812 and is believed to have ceased in 1814, as the last issue located was April 2, 1814. The periodical was suspended with the November 23, 1812 issue and resumed with the December 14, 1812 issue. The quote at the top of the first page is "The public good our end". The periodical's various authors included: Desnoues, Joseph, 1794?-1837. O'Connor, Thomas, 1770-1855. Hardcastle, John, 1778?-1835. Van Pelt, Peter, 1779?-1843. Wall, Stephen. Van Riper, Nicholas. Other authors are believed to be the American Antiquarian Society. Proprietors: T. O'Connor and S. Wall, 1812; T. O'Connor, 1812- . Printers: Hardcastle and Van Pelt, for T. O'Connor and S. Wall, Sept. 14-Oct. 5, 1812; J. Desnoues, Oct. 12, 1812- ; N. Van Riper, Nov. 6, 1813- . This issue was included in a bound volume of the Military Monitor and American Register. Other Dates included are: 1812 October 12 1812 October 19 1812 November 23 1812 December 14 1812 December 21 1813 January 11 1813 February 1 1813 March 29 1813 April 5 1813 April 12 1813 April 26 1813 May 31

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The Military Monitor was a weekly periodical that was published every Monday. The first issue was printed for August 17, 1812 and is believed to have ceased in 1814, as the last issue located was April 2, 1814. The periodical was suspended with the November 23, 1812 issue and resumed with the December 14, 1812 issue. The quote at the top of the first page is "The public good our end". The periodical's various authors included: Desnoues, Joseph, 1794?-1837. O'Connor, Thomas, 1770-1855. Hardcastle, John, 1778?-1835. Van Pelt, Peter, 1779?-1843. Wall, Stephen. Van Riper, Nicholas. Other authors are believed to be the American Antiquarian Society. Proprietors: T. O'Connor and S. Wall, 1812; T. O'Connor, 1812- . Printers: Hardcastle and Van Pelt, for T. O'Connor and S. Wall, Sept. 14-Oct. 5, 1812; J. Desnoues, Oct. 12, 1812- ; N. Van Riper, Nov. 6, 1813- . This issue was included in a bound volume of the Military Monitor and American Register. Other Dates included are: 1812 August 31 1812 October 12 1812 October 19 1812 November 23 1812 December 14 1812 December 21 1813 January 11 1813 February 1 1813 March 29 1813 April 5 1813 April 12 1813 April 26

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A weekly paper that was published from 1805 to 1814. War related news includes: Page 103 - Weekly Retrospect: Troop movements of Captain Morgan and a company of light dragoons from Niagara to Greenbush; report on the Battle of Queenston Heights including a casualty listing and a mention of the death of Major General Isaac Brock and Colonel McDonald and the American's respect for Brock; British attach of Fort Erie and the Village of Black Rock; the privateer Globe under Captain Murphy returning to Baltimore after capturing a British letter of marque; First Nation / Indian attacks near St. Louis; movements of General W. Harrison and army from Fort Defiance to the rapids of Miama (Miami). The rest of the newspaper contains literary works (poems and translations), essays (including on celibacy), marriages, deaths and other anecdotes. The motto on the front page states: "Visiting Every Flower with Labour Meet, and Gathering all its Treasures, Sweet by Sweet."

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A letter from Colonel Albert D. Shaw to Francis Lynde Stetson dated March 31, 1892. The letter is in regards to correspondence with the Attorney General in efforts to expedite the passing of an Act through Ontario Parliament. The act was introduced a week later (April 6, 1892) confirming the agreement between the Queen Vctoria Niagara Falls Park and the Canadian Niagara Power Company.

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Volumes of interest were published between 1812 and 1815 with articles about the War of 1812.

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Volumes of interest were published between 1812 and 1815 with articles about the War of 1812.

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Volumes of interest were published between 1812 and 1815 with articles about the War of 1812. The 1814 Aug. issues report events of the Battle of Chippewa.

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Volumes of interest were published between 1812 and 1815 with articles about the War of 1812.

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Volumes of interest were published between 1812 and 1815 with articles about the War of 1812.

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Volumes of interest were published between 1812 and 1815 with articles about the War of 1812.

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