The present invention relates to a method for the production of unsaturated fatty acids with at least two double bonds andor a method for the production of triglycerides with an increased content of polyunsaturated fatty acids with at least two double bonds. The drag is actively modulated by energy beams which may either increase or decrease the drag. The member has conductive springs attached to either end that are used to complete the electrical circuit with the battery and the lamp, while their compressive force is absorbed by a housing protecting the switch structure.