Stefan Svensson

Crystal structure and biological implications of a bacterial albumin binding module in complex with human serum albumin

Many bactericide species express surface proteins that interact with human serum albumin (HSA). Protein PAB from the anaerobic bacterium Finegoldia magna (formerly Peptostreptococcus magnus) represents one of these proteins. Protein PAB contains a domain of 53 amino acid residues known as the GA module. GA homologs are also found in protein G of group C and G streptococci. Here we report the crystal structure of HSA in complex with the GA module of protein PAB. The model of the complex was refined to a resolution of 2.7 Å and reveals a novel binding epitope located in domain II of the albumin molecule. The GA module is composed of a left-handed three-helix bundle, and residues from the second helix and the loops surrounding it were found to be involved in HSA binding. Furthermore, the presence of HSA-bound fatty acids seems to influence HSA-GA complex formation. F. magna has a much more restricted host specificity compared with C and G streptococci, which is also reflected in the binding of different animal albumins by proteins PAB and G. The structure of the HSA-GA complex offers a molecular explanation to this unusually clear example of bacterial adaptation.

A study of tactical patterns during fire fighting operations

Twenty experiments were performed in a three-room apartment, on the first floor of a three-storey apartment building with an attached staircase. The purpose of the experiments was to investigate various tactical patterns used during fire fighting operations, including suppression and ventilation procedures. As a fire source, eight standard wooden pallets were used. The temperature and pressure in the apartment, the weight of the fire source and the flow rate of water for suppression were recorded continuously. The results showed that positive pressure ventilation is a useful procedure, provided that it is used correctly and with caution. In addition, basic tactical principles were experimentally shown and validated.

Experimental study of fire ventilation during fire fighting operations

Fire ventilation measures taken by fire & rescue services, including positive pressure ventilation, were investigated. Fifteen tests were performed in a three-room apartment, with an attached staircase, on the first floor of a training facility. The fire source was a 0.5 m diameter pool of heptane. The temperature and pressure in the apartment, the weight of the fire source, and the flow through openings were recorded continuously. The tests showed that the rate of burning was increased by positive pressure ventilation. Also, positive pressure ventilation increases the temperature in rooms on the leeward side of the fire and reduces temperatures in rooms on the windward side of the fire. Safety and working conditions for fire fighters are improved by positive pressure ventilation, but it jeopardises the lives of anyone that might be trapped. The importance of command and control during fire fighting operations is prominent.

Command and control of fire and rescue operations in Sweden

The fire and rescue service in Sweden is primarily regulated by the civil protection act and the civil protection regulation which is primarily concerned with protection of the public against accidents. Stefan Svensson explains the legislation is designed to provide reasonable protection against accidents to people, property and the environment throughout the country taking into account local conditions. The national government cannot make any decisions about the level of protection locally. The legislation is a framework, which includes basic values and principles and to a lesser extent some detail about what should be done and how this should be accomplished, but these arrangements have to be agreed with the local self-governing system.