Phospholipid metabolism by phagocytic cells. Phospholipases A2 associated with rabbit polymorphonuclear leukocyte granules

Polymorphonuclear leukocytes obtained from sterile peritoneal exudates in rabbits contain two phospholipid-splitting activities (phosphatidylacylhydrolases EC 3.1.1.4), one most active at pH 5.5 and the other between pH 7.2 and 9.0. Hydrolysis of phospholipid was demonstrated using Escherichia coli labeled during growth with [1-(14)C]oleate and then autoclaved to inactivate E. coli phospholipases and to increase the accessibility of the microbial phospholipid substrates. The acid and alkaline phospholipase activities are both membrane bound, calcium dependent, and heat stable, and they appear to be specific for the 2-acyl position of phospholipids. Evidence was also obtained suggesting that the E. coli envelope phospholipids with oleate in position 2 are more readily degraded than those with palmitate. The two activities are associated with azurophilic as well as specific granules (obtained by zonal centrifugation) and with phagosomes (isolated after ingestion of paraffin particles by the granulocytes). Phospholipase A activities at pH 5.5 and pH 7.5 degrade the two major phospholipids of E. coli, phosphatidylethanolamine and phosphatidylglycerol, to the same extent, but the phospholipase activity at acid pH does not hydrolyze micellar dispersions of phosphatidylethanolamine. By contrast, phospholipase A(2) activity at pH 7.5 degrades both types of phosphatidylethanolamine substrates. Heparin and chondroitin sulfate inhibit phospholipase activity at pH 5.5 but have little effect on activity at pH 7.5. All detergents tested inhibited phospholipase activity, and both activities are inhibited by reaction products, free fatty acid and lysophosphatidylethanolamine. This product inhibition is only partially prevented by addition of albumin. Supernatant fractions of granulocyte homogenates contain a heat-labile inhibitor of granule phospholipase activity at pH 7.5. Boiling the fraction not only removes the inhibition but actually results in stimulation of hydrolysis at pH 7.5 as well as pH 5.5. These granule-associated phospholipase A activities of polymorphonuclear leukocytes differ in several of their properties from granule or lysosomal phospholipases of other phagocytic cells

The Effects of Mood on Individuals' Use of Structured Decision Protocols

This paper begins to answer the call to broaden current theories of individual decision-making by including in them the effects of human mood. Grounding our arguments in psychological literature on the effects of mood on information processing, motivation, and decision heuristics, we develop hypotheses about how mood can significantly affect individuals' use of structured decision protocols. In support of our hypotheses, results from an experimental study of complex decision-making suggest that, in situations where a structured decision protocol is the usual method of decision-making, individuals in moderately negative moods are significantly more likely than those in moderately positive moods to: (1) carefully execute all the steps of a structured decision protocol, (2) execute the steps of a structured decision protocol in the correct order, and (3) rely on the outcome of the structured decision protocol as the primary basis for the decision. We discuss these findings in terms of their implications for both organizational decision models and psychological models of mood and decision-making. In general, our findings help establish mood as an important variable in models of organizational decision-making and help shed light on often conflicting findings about the benefits of positive vs. negative mood for individual decision-making

Members' responses to organizational identity threats: Encountering and countering the business week rankings

This research investigates how organizational members respond to events that threaten their perceptions of their organization's identity. Using qualitative, interview, and records data, we describe how menebers from eight "top-20" business schools responded to the 1992 Business Week survey rankings of U.S. business schools. Our analysis suggests that the rankings posed a two-pronged threat to many members' perceptions of their schools' identities by (1) calling into question their perceptions of highly valued, core identity attributes of their schools, and (2) challenging their beliefs about their schools' standing relative to other schools. In response, members made sense of these threats and affirmed positive perceptions of their school's identity by emphasizing and focusing on their school's membership in selective organizational categories that highlighted favorable identity dimensions and interorganizational comparisons not recognized by the rankings. Data suggest that members' use of these categorization tactics depended on the level of identity dissonance they felt following the rankings. We integrate these findings with insights from social identity, self-affirmation, and impression management theories to develop a new framework of organizational identity management

Synthetic biology – The next phase of biotechnology and genetic engineering. Summary

For a good ten years now, the term "synthetic biology" (Synbio for short) has been used to describe research projects, methods and procedures for a "transformation" of natural organisms that goes further than was previously possible with the help of genetic engineering. The creation of (completely) artificial "biological" systems (synbio in the narrow sense) is envisaged, although their practical use is still a long way off and is therefore unlikely to have much social and political relevance in the coming years. The situation is quite different with synbio in the broader sense - understood as the next stage of biotechnology and genetic engineering, which includes in particular the recently developed methods of so-called genome editing (including CRISPR/Cas). Due to the increasingly simple and faster possibilities of targeted molecular biological modification of known organisms, a large number of applications in microorganisms, plants and animals can be expected in the coming years. As expected, the debate on the responsible use and necessary regulation of genetic engineering gained momentum in autumn 2015. The TAB report provides a comprehensive account of the state of research, development and application, safety and governance issues of synbio, as well as a detailed portrait of actors and perspectives of do-it-yourself biology. It places the debates on the potentials and perspectives of synbio in larger science, research and innovation policy contexts and elaborates central questions for the future and fields of action - including in the area of biosafety research and with a view to expanding the groups of actors in the planning and implementation of research programmes and projects