Stakeholder Salience for Small Businesses : A Social Proximity Perspective

This paper advances stakeholder salience theory from the viewpoint of small businesses. It is argued that the stakeholder salience process for small businesses is influenced by their local embeddedness, captured by the idea of social proximity, and characterised by multiple relationships that the owner-manager and stakeholders share beyond the business context. It is further stated that the ethics of care is a valuable ethical lens through which to understand social proximity in small businesses. The contribution of the study conceptualises how the perceived social proximity between local stakeholders and small business owner-managers influences managerial considerations of the legitimacy, power and urgency of stakeholders and their claims. Specifically, the paradoxical nature of close relationships in the salience process is acknowledged and discussed.Peer reviewe

NarK enhances nitrate uptake and nitrite excretion in Escherichia coli.

narK mutants of Escherichia coli produce wild-type levels of nitrate reductase but, unlike the wild-type strain, do not accumulate nitrite when grown anaerobically on a glucose-nitrate medium. Comparison of the rates of nitrate and nitrite metabolism in cultures growing anaerobically on glucose-nitrate medium revealed that a narK mutant reduced nitrate at a rate only slightly slower than that in the NarK+ parental strain. Although the specific activities of nitrate reductase and nitrite reductase were similar in the two strains, the parental strain accumulated nitrite in the medium in almost stoichiometric amounts before it was further reduced, while the narK mutant did not accumulate nitrite in the medium but apparently reduced it as rapidly as it was formed. Under conditions in which nitrite reductase was not produced, the narK mutant excreted the nitrite formed from nitrate into the medium; however, the rate of reduction of nitrate to nitrite was significantly slower than that of the parental strain or that which occurred when nitrite reductase was present. These results demonstrate that E. coli is capable of taking up nitrate and excreting nitrite in the absence of a functional NarK protein; however, in growing cells, a functional NarK promotes a more rapid rate of anaerobic nitrate reduction and the continuous excretion of the nitrite formed. Based on the kinetics of nitrate reduction and of nitrite reduction and excretion in growing cultures and in washed cell suspensions, it is proposed that the narK gene encodes a nitrate/nitrite antiporter which facilitates anaerobic nitrate respiration by coupling the excretion of nitrite to nitrate uptake. The failure of nitrate to suppress the reduction of trimethylamine N-oxide in narK mutants was not due to a change in the level of trimethylamine N-oxide reductase but apparently resulted from a relative decrease in the rate of anaerobic nitrate reduction caused by the loss of the antiporter system

Reversible dissociation of tryptophanase into protein subunits.

Crystalline tryptophanase from Escherichia coli strain B/1t7-A has been shown to behave as a single entity in the analytical ultracentrifuge with an S20, t, value of 9.65, whereas sucrose density gradient centrifugation of crude extracts of the organism showed that tryptophanase sedimented predominantly as a particle with S20, f value of 6.85. Since the crystalline enzyme was isolated in 60 per cent yield, it was suggested that two species of the enzyme coexist in crude extracts and are interconvertible. The sedimentation constant of a purified tryptophanase preparation from E. coli T3, a tryptophan auxotroph of E. coli K12, was determined to be 9.0S. Crude extracts of E. coli T3 also gave two peaks with sedimentation values 9.4S (minor peak) and 6.9S (major peak) by the sucrose density gradient method. A purified tryptophanase from Bacillus alvei has been shown4 to behave as a single peak in the analytical ultracentrifuge; the sedimentation coefficient was calculated to be 10.3S by extrapolation to infinite dilution. All of the sedimentation results cited above can be explained consistently by the observations reported herein. We describe some of our findings on the behavior of tryptophanases from E. coli T3 and B. alvei. Methods: The cell-free extracts, prepared from E. coli by sonic disintegration, and the purified enzyme from B. alvei4 were used as enzyme sources. The sucrose density gradient centrifugation studies were carried out essentially as described by Martin and Ames,5 except that 50 mM potassium phosphate buffer was used in place of 50 mM Tris-Cl wherever indicated. Pyridoxal phosphate was also included in all the gradients to a final concentration of 40 ,μM. Magnesium acetate was included (0.1 mMi) wherever mentioned. Catalase (Worthington Biochemical Corp., N. J.) was used as the reference standard. It was established in separate experiments in the analytical ultracentrifuge that the sedimentation constant of catalase (11.4S) was the same in either 50 mM potassium phosphate buffer or 50 mM Tris- Cl buffer. The tryptophanase and catalase activities were determined as described by Feiss and DeMoss, and Martin and Ames,5 respectively. Results: The purified enzyme from B. alvei sedimented as two peaks, a major peak with sedimentation constant 5.5S and a minor peak at 9.4S in a sucrose density gradient, prepared in 50 mM Tris-Cl. However, when potassium phosphate was used in place of Tris-Cl, the enzyme tended to aggregate predominantly to a larger particle with the sedimentation value of 9.4. The sedimentation behavior of the enzyme from E. coli also was examined in Tris-Cl and in potassium phosphate buffers, and the results with both enzymes are shown in Figures 1-4. The sedimentation constants obtained for the enzymes from E. coli and B. alvei in a series of experiments are presented in Table 1. The presence of Mg++ had no significant influence on the sedimentation constants observed

The connectionist self in action

Philosophy, Philosophy of mind, Connectionism, Agency, Freedom, Rational action, Narrative self, Searle,