Negotiation in strategy making teams : group support systems and the process of cognitive change

This paper reports on the use of a Group Support System (GSS) to explore at a micro level some of the processes manifested when a group is negotiating strategy-processes of social and psychological negotiation. It is based on data from a series of interventions with senior management teams of three operating companies comprising a multi-national organization, and with a joint meeting subsequently involving all of the previous participants. The meetings were concerned with negotiating a new strategy for the global organization. The research involved the analysis of detailed time series data logs that exist as a result of using a GSS that is a reflection of cognitive theory

Conjugation to the Cell-Penetrating Peptide TAT Potentiates the Photodynamic Effect of Carboxytetramethylrhodamine

Cell-penetrating peptides (CPPs) can transport macromolecular cargos into live cells. However, the cellular delivery efficiency of these reagents is often suboptimal because CPP-cargo conjugates typically remain trapped inside endosomes. Interestingly, irradiation of fluorescently labeled CPPs with light increases the release of the peptide and its cargos into the cytosol. However, the mechanism of this phenomenon is not clear. Here we investigate the molecular basis of the photo-induced endosomolytic activity of the prototypical CPPs TAT labeled to the fluorophore 5(6)-carboxytetramethylrhodamine (TMR).We report that TMR-TAT acts as a photosensitizer that can destroy membranes. TMR-TAT escapes from endosomes after exposure to moderate light doses. However, this is also accompanied by loss of plasma membrane integrity, membrane blebbing, and cell-death. In addition, the peptide causes the destruction of cells when applied extracellularly and also triggers the photohemolysis of red blood cells. These photolytic and photocytotoxic effects were inhibited by hydrophobic singlet oxygen quenchers but not by hydrophilic quenchers.Together, these results suggest that TAT can convert an innocuous fluorophore such as TMR into a potent photolytic agent. This effect involves the targeting of the fluorophore to cellular membranes and the production of singlet oxygen within the hydrophobic environment of the membranes. Our findings may be relevant for the design of reagents with photo-induced endosomolytic activity. The photocytotoxicity exhibited by TMR-TAT also suggests that CPP-chromophore conjugates could aid the development of novel Photodynamic Therapy agents

On the Role of the Difference in Surface Tensions Involved in the Allosteric Regulation of NHE-1 Induced by Low to Mild Osmotic Pressure, Membrane Tension and Lipid Asymmetry

The sodium-proton exchanger 1 (NHE-1) is a membrane transporter that exchanges Na+ for H+ ion across the membrane of eukaryotic cells. It is cooperatively activated by intracellular protons, and this allosteric regulation is modulated by the biophysical properties of the plasma membrane and related lipid environment. Consequently, NHE-1 is a mechanosensitive transporter that responds to osmotic pressure, and changes in membrane composition. The purpose of this study was to develop the relationship between membrane surface tension, and the allosteric balance of a mechanosensitive transporter such as NHE-1. In eukaryotes, the asymmetric composition of membrane leaflets results in a difference in surface tensions that is involved in the creation of a reservoir of intracellular vesicles and membrane buds contributing to buffer mechanical constraints. Therefore, we took this phenomenon into account in this study and developed a set of relations between the mean surface tension, membrane asymmetry, fluid phase endocytosis and the allosteric equilibrium constant of the transporter. We then used the experimental data published on the effects of osmotic pressure and membrane modification on the NHE-1 allosteric constant to fit these equations. We show here that NHE-1 mechanosensitivity is more based on its high sensitivity towards the asymmetry between the bilayer leaflets compared to mean global membrane tension. This compliance to membrane asymmetry is physiologically relevant as with their slower transport rates than ion channels, transporters cannot respond as high pressure-high conductance fast-gating emergency valves

Strategic options development and analysis

Strategic Options Development and Analysis (SODA) enables a group or individual to construct a graphical representation (map) or a problematic situation, and thus explore options and their ramifications with respect to a complex system of goals or objectives. In addition the approach aims to help groups arrive at a negotiated agreement about how to act to resolve the situation. It is based upon the use of causal mapping – a formally constructed means-ends network. Because the map has been constructed using the natural language of the problem owners it becomes a model of the situation that is ‘owned’ by those who define the problem. The use of formalities for the construction of the model makes it amenable to a range of analyses encouraging reflection and a deeper understanding. These analyses can be used in a ‘rough and ready’ manner by visual inspection or through the use of specialist causal mapping software. Each of the analyses helps a group or individual discover important features of the problem situation. And these features facilitate agreeing a good solution. The SODA process is aimed at helping a group learn about the situation they face before they reach agreements. Most significantly the exploration through the causal map leads to a higher probability of more creative solutions and promotes solutions that are more likely to be implemented because the problem construction process is more likely to include richer social dimensions about the blockages to action and organizational change. The basic theories that inform SODA derive from cognitive psychology and social negotiation, where the model acts as a continuously changing representation of the problematic situation (a transitional object) – changing as the views of a person or group shift through learning and exploration. This chapter jointly written by two leading practitioner academics and the original developers of SODA, Colin Eden and Fran Ackermann, describe the SODA approach as it is applied in practice