Modeling traffic jams in intracellular transport in axons

Irregularities in intracellular traffic in axons caused by mutations of molecular motors may lead to “traffic jams”, which often result in swelling of axons causing various neurodegenerative diseases. The purpose of this paper is to suggest a model of the formation of traffic jams in axons during molecular-motor-assisted transport of intracellular organelles utilizing transport equations developed in Smith and Simmons [1], which describe the motion of intracellular particles under the combined action of diffusion and motor-driven transport. According to this model, large intracellular organelles are transported in the cytoplasm by a combined action of diffusion and motor-driven transport. In an axon, organelles are transported away from the neuron’s body toward the axon’s terminal by kinesin-family molecular motors running on tracks composed by microtubules; old and used components are carried back toward neuron’s body by dynein-family molecular motors. Binding/detachment kinetic processes between the organelles and microtubules are specified by first rate reaction constants; these lead to coupling between the three organelle concentrations

Hydrodynamic modeling of traffic jams in intracellular transport in axons

Irregularities in intracellular traffic in axons caused by mutations of molecular motors may lead to “traffic jams”, which often result in swelling of axons causing such neurodegenerative diseases as Alzheimer’s disease and Down syndrome. Hence, it is of particular interest to mathematically model the formation of traffic jams in axons. This paper adopts the hydrodynamic continuity equations for intracellular transport of organelles as developed by Smith and Simmons [1] whereas the Kerner and Konhäuser [2] model for traffic jams in highway traffic is applied to predict the velocity field. It is observed that combination of the two sets of equations can comprehensively predict the traffic jams in axons without the need to any additional assumption or modification

Chinese multinationals: host country factors and foreign direct investment location

The study of Chinese multinationals (MNEs) is becoming one of the most promising research topics in the international business literature. After outlining the distinctive characteristics of the internationalization process of Chinese MNEs, this chapter analyzes the influence of various host country factors on the location of Chinese outward foreign direct investment (FDI). From a sample of 189 outward FDI decisions made by 35 mainland Chinese firms in 63 countries, our results show that host market size and the existence of overseas Chinese in the host country are positively associated with the number of Chinese FDIs. However, greater difficulty in doing business and host country political risk have no effect

Internalisation Theory and outward direct investment by emerging market multinationals

The rise of multinational enterprises from emerging countries (EMNEs) poses an important test for theories of the multinational enterprise such as internalisation theory. It has been contended that new phenomena need new theory. This paper proposes that internalisation theory is appropriate to analyse EMNEs. This paper examines four approaches to EMNEs—international investment strategies, domestic market imperfections, international corporate networks and domestic institutions—and three case studies—Chinese outward FDI, Indian foreign acquisitions and investment in tax havens—to show the enduring relevance and predictive power of internalisation theory. This analysis encompasses many other approaches as special cases of internalisation theory. The use of internalisation theory to analyse EMNEs is to be commended, not only because of its theoretical inclusivity, but also because it has the ability to connect and to explain seemingly desperate phenomena

Run Away or Stick Together? The Impact of Organization-Specific Adverse Events on Alliance Partner Defection

Alliances are inter-organizational relationships wherein partners agree to engage in joint action and share benefits and burdens. But when might an adverse event that strikes one partner become too burdensome for another partner? Extant theories of alliance instability provide incomplete answers, which is problematic: for stricken organizations, anticipating whether their non-stricken partners will remain in the alliance can be essential for survival. Integrating insights from alliance dynamics and organizational stigma literatures, we theorize how an organization-specific adverse event affects a non-stricken partner's decision to continue with or defect from an alliance by considering factors that shift the balance between cohesive and disruptive forces. We propose that high stigmatization risk will increase the probability of partner defection through two disruptive mechanisms: relational uncertainty and stigma anxiety. Building on the idea that the same factors contributing to alliance formation may also condition partner defection, we theorize about the roles of partner resource interdependencies, relational embeddedness, and perceived partner similarity in amplifying or attenuating disruptive mechanisms triggered by an adverse event. We extend the research on partner defection and alliance instability by advancing an event-based view of alliance instability and specifying the conditions under which an alliance partner might defect