16 resultados para Cornelia, mother of the Gracchi, b. ca. 175 B.C.
em Brock University, Canada
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Marine palynology and benthic and planktonic foraminiferal geochemistry are combined to reveal long- and short-term (Milankovitch-scale) paleoceanographic changes across the upper half of the Olduvai Subchron (ca. 1.86--1.77 Ma, lower Pleistocene) in DSDP Hole 603C from the lower New Jersey continental rise. Planktonic foraminiferal Mg/Ca ratios reveal annual sea-surface temperatures between 14.5° and 25°C, whereas modern values vary between 16° and 20°e. Despite evidence of downslope transport in much of the studied interval, dinoflagellate cyst and acritarch assemblages appear to reflect fluctuating temperate to subtropical water masses. These assemblages comprise both neritic and oceanic species, and are marked by a transition upsection from warm conditions, dominated by Lingulodinium machaerophorum, Polysphaeridium zoharyi and Cymatiosphaera? invaginata, to cooler conditions dominated by Filisphaera filifera. Combining dinoflagellate cyst proxies with planktonic foraminiferal geochemistry allows downslope transport events to be recognized during glacial episodes, and events dominated by intensified bottom-water circulation during interglacial episodes. Sixtytwo in-situ dinoflagellate cyst and acritarch taxa were recorded including several not previously described.
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The Pater metavolcanic suite (PVS) was extruded as part O'f the basal Pater Formation of the Huronian Supergroup ca. 2.4 Ga. They Ars classified as wi thin-plate tholeiites associated with an immature ri-fting episode, and are inter layered with associated vol cani clastic and metasedimentary units. Post-solidif ication alteration caused redistribution o-f the alkalies, Sr, Rb, Ba, Cu, and SiO^. Ce, Y, Zr, CFezOs (as total Fe), Al^Os, TiOa, and, PaOa are considered to have remained essentially immobile in least altered samples. Petrogenetic modelling indicates the PVS was derived from the partial melting of two geochemical ly similar sources in the sub-continental lithosphere. Fractionation was characterized by an oli vine-plagioclase assemblage and a sub-volcanic plagioclase-clinopyroxene assemblage. A comparative study indicates that enrichment of the postulated Huronian source cannot be reconciled by Archean contamination. Enrichment is thought to have been caused by hydrous veined metasomatic heterogeneities in the sub-continental lithosphere, generated by an Archean subduct ion event before 2.68 Ga.
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Exchange reactions between molecular complexes and excess acid or base are well known and have been extensively surveyed in the literature(l). Since the exchange mechanism will, in some way involve the breaking of the labile donor-acceptor bond, it follows that a discussion of the factors relating to bonding in molecular complexes will be relevant. In general, a strong Lewis base and a strong Lewis acid form a stable adduct provided that certain stereochemical requirements are met. A strong Lewis base has the following characteristics (1),(2) (i) high electron density at the donor site. (ii) a non-bonded electron pair which has a low ionization potential (iii) electron donating substituents at the donor atom site. (iv) facile approach of the site of the Lewis base to the acceptor site as dictated by the steric hindrance of the substituents. Examples of typical Lewis bases are ethers, nitriles, ketones, alcohols, amines and phosphines. For a strong Lewis acid, the following properties are important:( i) low electron density at the acceptor site. (ii) electron withdrawing substituents. (iii) substituents which do not interfere with the close approach of the Lewis base. (iv) availability of a vacant orbital capable of accepting the lone electron pair of the donor atom. Examples of Lewis acids are the group III and IV halides such (M=B, AI, Ga, In) and MX4 - (M=Si, Ge, Sn, Pb). The relative bond strengths of molecular complexes have been investigated by:- (i) (ii) (iii) (iv) (v] (vi) dipole moment measurements (3). shifts of the carbonyl peaks in the IIIR. (4) ,(5), (6) .. NMR chemical shift data (4),(7),(8),(9). D.V. and visible spectrophotometric shifts (10),(11). equilibrium constant data (12), (13). heats of dissociation and heats of reactions (l~), (16), (17), (18), (19). Many experiments have bben carried out on boron trihalides in order to determine their relative acid strengths. Using pyridine, nitrobenzene, acetonitrile and trimethylamine as reference Lewis bases, it was found that the acid strength varied in order:RBx3 > BC1 3 >BF 3 • For the acetonitrile-boron trihalide and trimethylamine boron trihalide complexes in nitrobenzene, an-NMR study (7) showed that the shift to lower field was. greatest for the BB~3 adduct ~n~ smallest for the BF 3 which is in agreement with the acid strengths. If electronegativities of the substituents were the only important effect, and since c~ Br ,one would expect the electron density at the boron nucleus to vary as BF3<BC1~ BBr 3 and therefore, the acid strength would vary as BF~BC1)BBr3: However, for the boron trihalides, the trend is in the opposite direction as determined experimentally. Considerable back-bonding (20), (21) between the halogen and the boron atoms has been proposed as the predominating factor, i.e. ~rt- back-bond between a lone electron pair on the halogen and the vacant orbital on the boron site. The degree of back-bonding varies inversely as the bo~on halogen distance and one would therefore expect the B-F bond to exhibit greater back-bonding character than the B-Cl or B-Br bonds. Since back-bonding transfers electron density from substituent to the boron atom site, this process would be expected to weaken the Lewis acid strength. This explains the Lewis acid strength increasing in the order BF 3 BC1 3 BBr 3 . When the acetonitrile boron trihalide complex is formed, the boron atom undergoes ~_cbange of hybridization from sp2 to sp3. From a linear relationship between the heat of formation of ethyl acetate adducts and the shift in the carbonyl I.R. stretch, Drago (22) et al have proposed that the angular di~tortion of the X-B-X bonds from sp2 (12 ) to sp3 (10 hybridization is proportional to the amount of charge transferred, i.e. to the nature of the base, and they have rejected the earlier concept of reorganization energy in explaining the formation of the adduct bond (19).
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February 28, 1815. Printed by order of the Senate of the United States. Printed be Roger C. Weightman
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February 13, 1815. Printed by order of the Senate of the United States. Printed by Roger C. Weightman
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The quality of the mother-child relationship was examined in relation to joint planning, maternal teaching strategies, maternal emotional support, mutual positive affect and attachment security. Fifty-five grade five children and their mothers participated in a laboratory session comprised of various activities and completed questionnaires to evaluate attachment security. Joint planning and social problem solving were assessed observationally during an origami task. Problem solving effectiveness was unrelated to maternal teaching strategies, maternal encouragement and mutual positive affect. A marginally significant relationship was found between maternal encouragement and active child participation. Attachment security was found to be significantly related to sharing of responsibility during local planning, but only for child autonomous performance. An examination of conditional probabilities revealed that mutual positive affect did not increase the likelihood of subsequent mother-child dyadic regulation. However, mutual positive affect was found to be significantly related to both active child participation and dyadic regulation. The hypothesis predicting a mediational model was not supported. The implications of these findings in the theoretical and empirical literature were considered and suggestions for future research were made.
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Presence of surface glycoprotein in Piptocephalis virginiana that recognizes the host glycoproteins band c, reported earlier from our laboratory, was detected by immunofluorescence microscopy. Germinated spores of P. virginiana treated with Mortierella pusilla cell wall protein extract, primary antibodies prepared against glycoproteins band c and FITC-goat anti-rabbit IgG conjugate showed fluorescence. This indicated that on the surfaces of the biotrophic mycoparasite P. virginiana , there might be a complementary molecule which recognizes the glycoproteins band c from M. pusilla. Immunobinding analysis identified a glycoprotein of Mr 100 kDa from the mycoparasite which binds with the host glycoproteins band c, separately as well as collectively. Purification of this glycoprotein was achieved by (i) 60% ammonium sulfate precipitation, (ii) followed by heat treatment, and (iii) Sephadex G-IOO gel filtration. The glycoprotein was isolated by preparative polyacrylamide gel electrophoresis by cutting and elution. The purity of the protein ·was ascertained by SDS-PAGE and Western blot analysis. Positive reaction to periodic acid-Schiff reagent revealed the glycoprotein nature of this 100 kDa protein. Mannose was identified as a major sugar component of this glycoprotein by using a BoehringerMannheim Glycan Differentiation Kit. Electrophoretically purified glycoprotein was used to raIse polyclonal antibody in rabbit. The specificity of the antibody was determined by dot-immunobinding test and western-blot analysis. Immunofluorescence mIcroscopy revealed surface localization of the protein on the germ tube of Piptocephalis virginiana. Fluorescence was also observed at the surfaceJ of the germinated spores and hyphae of the host, M. pusilla after treatment with complementary protein from P. virginiana, primary antibody prepared against the complementary protein and FITC-goat anti-rabbit IgG conjugate.
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The effec s of relative water level changes in Lake Ontario were detected in the ysical, chemical and biological characteristics of the sediments of the Fifteen, Sixteen and Twenty Mile Creek lagoonal complexes. Regional environmental changes have occurred resulting in the following sequence of sediments in the three lagoons and marsh. From the base up they are; (I) Till,(2) Pink Clay, (3) Bottom Sand, (4) Gyttja, (5) Orange Sandy Silt, (6) Brown Clay and (7) Gray Clay. The till was only encountered in the marsh and channel; however, it is presumed to occur throughout the entire area. The presence of diatoms and sponge spicules, the vertical and ongitudinal uniformity of the sediment and the stratigr ic position of the Pink Clay indicate that it has a glacial or post-glacial lacustrine origin. Overl ng the Pink Clay or Till is a clayey, silty sand to gravel. The downstream fining and unsorted nature of this material indicate that it has a fluvial/deltaic origin. Water levels began rising in the lagoon 3,250 years ago resulting in the deposition of the Gyttja, a brown, organic-rich silty clay probably deposited in a shallow, stagnant environment as shown by the presence of pyrite in the organic material and relatively high proportions of benthic diatoms and grass pollen. Increase in the rate of deposition of the Gyttja on Twenty Mile Creek and a decrease in the same unit on Sixteen Mile Creek is possibly the result of a capture of the Sixteen Mile Creek by the Twenty Mile Creek. The rise in lake level responsible for the onset and transgression of this III unit may have been produced by isostatic rebound; however, the deposition also corresponds closely to a drop in the level of Lake Huron and increased flow through the lower lakes. The o ange Sandy Silt, present only in the marsh, appears to be a buried soil horizon as shown by oxidized roots, and may be the upland equivalant to the Gyttja. Additional deepening resulted in the deposition of Brown Clay, a unit which only occurs at the lakeward end of the three lagoons. The decrease in grass pollen and the relatively high proportion of pelagic diatoms are evidence for this. The deepening may be the result of isostatic rebound; however, the onset of its deposition at 1640 years B.P. is synchronous in the three lagoons and corresponds to the end of the subAtlantic climatic episode. The effects of the climatic change in southern Ontario is uncertain. Average deposition rates of the Brown Clay are similar to those in the upper Gyttja on Sixteen Mile Creek; however, Twenty Mile Creek shows lower rates of the Brown Clay than those in the upper Gyttja. The Gray Clay covers the present bottom of the three lagoons and also occurs in the marsh It is inter1aminated wi sand in the channels. Increases in the rates of deposi ion, high concentrations of Ca and Zn, an Ambrosia rise, and an increase in bioturbation possibly due to the activities of the carp, indicate th this unit is a recent deposit resulting from the activities of man.
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Jet-cooled, laser-induced phosphorescence excitation spectra (LIP) of thioacetaldehyde CH3CHS, CH3CDS, CD3CHS and CD3CDS have been observed over the region 15800 - 17300 cm"^ in a continuous pyrolysis jet. The vibronic band structure of the singlet-triplet n -* n* transition were attributed to the strong coupling of the methyl torsion and aldehydic hydrogen wagging modes . The vibronic peaks have been assigned in terms of two upper electronic state (T^) vibrations; the methyl torsion mode v^g, and the aldehydic hydrogen wagging mode v^^. The electronic origin O^a^ is unequivocally assigned as follows: CH3CHS (16294.9 cm"'' ), CH3CDS (16360.9 cm"'' ), CD3CHS (16299.7 cm"^ ), and CD3CDS (16367.2 cm"'' ). To obtain structural and dynamical information about the two electronic states, potential surfaces V(e,a) for the 6 (methyl torsion) and a (hydrogen wagging) motions were generated by ab initio quantum mechanical calculations with a 6-3 IG* basis in which the structural parameters were fully relaxed. The kinetic energy coefficients BQ(a,e) , B^(a,G) , and the cross coupling term B^(a,e) , were accurately represented as functions of the two active coordinates, a and 9. The calculations reveal that the molecule adopts an eclipsed conformation for the lower Sq electronic state (a=0°,e=0"') with a barrier height to internal rotation of 541.5 cm"^ which is to be compared to 549.8 cm"^ obtained from the microwave experiment. The conformation of the upper T^ electronic state was found to be staggered (a=24 . 68° ,e=-45. 66° ) . The saddle point in the path traced out by the aldehyde wagging motion was calculated to be 175 cm"^ above the equilibrium configuration. The corresponding maxima in the path taken by methyl torsion was found to be 322 cm'\ The small amplitude normal vibrational modes were also calculated to aid in the assignment of the spectra. Torsional-wagging energy manifolds for the two states were derived from the Hamiltonian H(a,e) which was solved variationally using an extended two dimensional Fourier expansion as a basis set. A torsionalinversion band spectrum was derived from the calculated energy levels and Franck-Condon factors, and was compared with the experimental supersonic-jet spectra. Most of the anomalies which were associated with the interpretation of the observed spectrum could be accounted for by the band profiles derived from ab initio SCF calculations. A model describing the jet spectra was derived by scaling the ab initio potential functions. The global least squares fitting generates a triplet state potential which has a minimum at (a=22.38° ,e=-41.08°) . The flatter potential in the scaled model yielded excellent agreement between the observed and calculated frequency intervals.
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On leaf preceding t. p.: Who was Isaac Brock?
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On leaf preceding t. p.: Who was Isaac Brock? Printed by Clarke
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Benjamin Bates was a member of the Religious Society of Friends, and served as Clerk of the Society at the time that the Memorial and Petition was written.
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Benjamin Bates was a member of the Religious Society of Friends, and served as Clerk of the Society at the time that the Memorial and Petition was written.
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Black and white photograph, mounted on board, 13 cm x 20 cm of the B Squadron of the G.G.B.G. [Governor General’s Body Guard] at Niagara.
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Letter to Mr. W. D. Woodruff who is listed as the Treasurer of the B.N. and T. Railway Company from H.H. Collier, Barrister regarding items that have been paid out of the account, Jan. 16, 1911.