Type IV secretion is used by pathogenic microorganisms to transfer effector macromolecules to eukaryotic target cells. The VirB/D4 apparatus of Agrobacterium tumefaciens transfers DNA and proteins to plant cells. We postulated that the cell pole is the site of assembly of the A. tumefaciens type IV apparatus. Using immunofluorescence microscopy, we now demonstrate that 10 of the VirB proteins l...

Scholars who view organizational, social, and technological systems as sets of interdependent decisions have increasingly used simulation models from the biological and physical sciences to examine system behavior. These models shed light on an enduring managerial question: how much exploration is necessary to discover a good configuration of decisions? The models suggest that, as interactions ...

This paper raises concerns that natural language front ends for computer systems can limit a researcher's scope of thinking, yield inappropriately complex systems, and exaggerate public fear of computers. Alternative modes of computer use are suggested and the role of psychologically oriented controlled experimentation is emphasized. Research methods and recent experimental results are briefly ...

Cellular automata are discrete dynamical systems characterized by simple local interactions among their components which are able to produce complex global behaviors, reason why they have been used to simulate natural and artificial systems and for implementing new paradigms of unconventional computing [I, 21. A classical study in dynamical systems is to understand reversible properties; in cel...

There are two dominant approaches to describe and understand the anatomy of complete health and well-being systems internationally. Yet, neither approach has been able to either predict or explain occasional but dramatic crises in health and well-being systems around the world and in developed emerging market or developing country contexts. As the impacts of such events can be measured not simp...

In biotechnology has been concentrated to review alternative routes for the production of natural compounds. Plant cell culture systems are viable alternatives for the production of secondary metabolites that are of commercial importance in food and pharmaceutical industries. However, relatively very few cultures synthesize these compounds over extended periods in amounts comparable to those fo...

AIMS AND OBJECTIVES This study aims to develop an intervention and related conceptual framework for developing shared care for patients with long-term mental illness, and to provide a case study of the development of a complex intervention in primary care. METHODS A pragmatic iterative design involved a literature review and focus groups followed by a formative evaluation including reflection...

In biotechnology has been concentrated to review alternative routes for the production of natural compounds. Plant cell culture systems are viable alternatives for the production of secondary metabolites that are of commercial importance in food and pharmaceutical industries. However, relatively very few cultures synthesize these compounds over extended periods in amounts comparable to those fo...