Showing papers by "Aix-Marseille University published in 1974"

Innovation in the Service Sector: Some Empirical Findings

Abstract: The service economy and its associated marketing practices has been receiving considerable attention in the marketing literature [2, 3, 8, 9, 10]. The primary impetus for this recognition has come from the increased importance of services to the economy as a whole [2, 17]. The nature of services has been found to cause some variations in the application of marketing concepts to services as compared with products. For instance, communication strategies for services may differ from those used for products since services cannot be displayed and are often difficult to demonstrate [4, p. 9]. These differences between products and services might also imply differences in consumer behavior patterns between the two areas. The local and personal nature of most services suggests that consumers may utilize different information sources to learn about new services than they do for products. In addition, the nonstandardized and intangible nature of services [9, pp. 34-5] could imply consumer application of different evaluative criteria and thus require different types of consumer expertise in the evaluation process. The study reported here attempts to determine the characteristics of innovators in one area of the service industry-retailing. The marketing literature contains several studies that have provided information on the characteristics of innovators in various product areas, many of which are summarized in [11]. However, to date the only studies of innovation in the service sector have concerned the adoption of service innovations by firms [8, 19] and word-of-mouth communication patterns of innovators of an automotive diagnostic service [1 ]. A related area of diffusion of innovation research has concerned the extent to which change agents (innovators and opinion leaders) exist across product

31P-Nuclear Magnetic Resonance Study of ATP and ATP-G-Actin: Direct Evidence for Pβ and Pγ Involvement in Nucleotide Binding

Abstract: The binding of adenosine 5’-triphosphate (ATP) to rabbit muscle G-actin in the presence of calcium has been studied by 31P Fourier transform NMR (40.5 MHz) in the pH 6.5 to 10.5 range. On the basis of line width measurements, it is shown that the tightest binding is reached around pH 8.5. Spin lattice (T 1 ) and spin-spin (T 2 ) relaxation times have been measured for each of the three phosphorus atoms of free and bound ATP. This study provides direct spectroscopic evidence for the prime importance of Pβ and Pγ in ATP binding to G-actin through a calcium bridge.

The mechanism of the exclusion of sodium ions and the concentration of potassium ions by guinea-pig cerebral cortex slices.

Abstract: —Guinea pig cerebral slices were incubated in oxygenated Krebs-Ringer bicarbonate glucose saline for periods of 1 s to 60 min, and their swelling and Na+ and K+ cone were measured. The swelling was at the rate of 8 per cent for the 1st min, and 0·8 per cent for the next 29 min; it fell significantly during the subsequent 30 min (P= 0·05). The Na+ and K+ concn in the tissue fluctuated during the 1st min of incubation, but the Na+ concn had risen to a mean of 108 mm after 1 min incubation and the K+ concn had fallen to a mean of 52 mm by 3 min. The concentrations of these cations did not change significantly after these times. Cerebral slices were also incubated for 30 min in isotonic media modified such that Na+, + K+, Na++ choline+, or K++ choline+ always added up to 150 mm. It was found that about half of the swelling (20-25 per cent) was independent of the Na+ or K+ concn and a further 20-25 per cent of the swelling varied with the cations only if Na+ and K+ were both present and was a function of the K+ concn in the medium (0·15 per cent m-mol). The Na+ concn in the tissue was a mean 8·4 mm after incubation in a Na+-free medium and 7·1 mm in K+ after incubation in a K+-free medium. Cerebral slices in the presence of Na++ K+ excluded one molecule of Na+ for every four molecules in the incubating medium; they accumulated K+ from the medium until the concn in the medium exceeded 130 mm.