Showing papers by "Duquesne University published in 1974"
55 citations
TL;DR: The correlation of activity with the presence of an added g-atom of Fe(2+)/mol leads to the conclusion that active aconitase has only one active site per mol.
Abstract: Aconitase activated with Fe2+, cysteine and ascorbate incorporates 1 g-atom of Fe2+/mol. Loss of this Fe2+ by transfer to ferrozine, a Fe2+ chelator, results in loss of activity. Ascorbate increases the rate of transfer of the essential Fe2+ whereas citrate retards the rate of transfer. Transfer of Fe2+ from inactive aconitase, 2 g-atoms of Fe/mol, can be accomplished in the presence of urea and ascorbate. The correlation of activity with the presence of an added g-atom of Fe2+/mol leads to the conclusion that active aconitase has only one active site per mol.
30 citations
TL;DR: The electron spin resonance spectrum, g 4.25, and the low molar relaxivity, 473m(-1).s(-1), of water H(+) suggest the presence of high-spin Fe(III) unco-ordinated to water in the enzyme.
Abstract: Comparison of pig heart aconitase (Kennedy et al., 1972) with yeast (Candida lipolytica) aconitase (Suzuki et al., 1973) reveals similarities in molecular weight and iron content but not in sulphide content. Comparison with the Mildvan & Villafranca (1971) pig heart aconitase preparation reveals differences in iron ligands, specific activity and other properties; these differences possibly arise from protein association as pig heart protein associates under a variety of conditions. The electron spin resonance spectrum, g 4.25, and the low molar relaxivity, 473m(-1).s(-1), of water H(+) suggest the presence of high-spin Fe(III) unco-ordinated to water in the enzyme. The iron chromophore on acid titration at 320nm gives a curve with an inflexion at pH4.2. Ten of 16 expected thiol equivalents are titrated with p-hydroxymercuribenzoate suggesting the presence of cystine as well as cysteine residues. Inhibition of the activation of inactive (activatable) enzyme is sigmoidally related to the molar ratio, p-hydroxymercuribenzoate/enzyme with 10-11mol of mercurial compound causing complete inhibition. Active enzyme, free from activating reagents, requires high molar ratios of mercurial compound for rapid inhibition. In terms of p-hydroxymercuribenzoate the enzyme then lacks an essential thiol group.
19 citations
TL;DR: Fischler and Rizozo as discussed by the authors pointed out that special education, like all of its behavioral-science relatives, is approaching a turning point, and they generally advocate being less mechanistic and simplistic.
Abstract: CONSTANCE T. FISCHER, Ph.D. ALFONSO A. RIZZO, Ph.D. Duquesne University Special education, like all of its behavioral-science relatives, is approaching a turning point. Initially its foundations in the physicalistic sciences enhanced its establishment as a specialized area with its own tools, language, constructs, controversies, clientele, and accomplishments. But now this same commitment to being scientific primarily in the quantitative, objectivistic tradition of nineteenth century physical sciences has carried special education to a point of limited and sometimes distressing returns. Although the resultant calls for methodological correctives have been notably ineffective for want of a new foundation, they generally advocate being less mechanistic and simplistic.
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TL;DR: It is hoped that in the field of product liability such joint efforts will lead to a more sophisticated and technologically sound litigation process, one in which the technologist can be true to himself while operating within a strong and responsive adversary system.
Abstract: The refinement of the product liability litigation process requires a continuing substantive dialogue between the legal and technical communities. The common problem-solving orientation of the two disciplines bodes well for such interaction. We have shared in the exciting beginnings of this legaltechnical interaction (7) and hope that in the field of product liability such joint efforts will lead to a more sophisticated and technologically sound litigation process, one in which the technologist can be true to himself while operating within a strong and responsive adversary system.
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TL;DR: The assassination and the investigation and the official findings are compared and conclusions are summarized.
TL;DR: The Personal Orientation Inventory (G), a measure of self-actualization which has 12 sub-scales, was administered to 115 marricd couples and no sex differences were found.
Abstract: A number of studies have reported sex differences for measures of self-concept and self-actualization (1, 2, 3, 5, 6 ) . Difterences were almost always in favor of female Ss. The Personal Orientation Inventory (G), a measure of self-actualization which has 12 sub-scales, was administered to 115 marricd couples. On a t test for correlated means no sex differences were found rhough males did slightly berter on 8 scales, females on 4.
TL;DR: In this paper, the authors demonstrate that a prohibitive tariff on used vehicles might reduce employment in the tariff levying nation's automotive industry, increase that nation's demand for foreign exchange, and violate stated (egalitarian) income distribution goals.
Abstract: One of the protective devices used by less developed nations to stimulate their automotive industries is a prohibitive tariff on used vehicles. The purpose of this note is to demonstrate that this restriction, via adjustments in the stock and age composition of vehicles, might reduce employment in the tariff levying nation's automotive industry, might increase that nation's demand for foreign exchange, and will violate stated (egalitarian) income distribution goals. The behaviour of the individual vehicle consumer will be analyzed first and market consumption adjustments brought about by various vehicle tariffs will be determined. Supply characteristics of the automotive industry are then presented, and the employment effects of a prohibitive tariff on used vehicles will be examined. Balance of payments and income redistribution effects are briefly considered.
TL;DR: The β-lactamase-catalyzed hydrolysis of penicillins can be followed by a novel NMR method and a ternary enzyme-substrate-AMP (ESA) complex is formed which reacts faster than ES.