aged aging animalbehavior autonomicnervoussystem biochemicalphenomena bioinformatics biologicalmodels biologicalsystems biology bodyfluidflow bodyfluids catalysis cellphysiologicalphenomena cellphysiologicalprocesses cellphysiology computationalbiology congresses controltheory dataprocessing electronicbehaviorcontrol electrotherapeutics enzymeactivation enzymes feedback(psychology) feedbackcontrolsystems forecasts histology mathematicalmodels medical microbialmetabolism microbialmetabolites molecularbiology muscle musclecontraction myocardium neuraltransmission neurochemistry neurotransmitteragents peptides photosynthesis physiologicaleffect physiologicalfeedback physiology qu105g992d1975 qu135h224e1982 qu68r3441981 qv126p5441979n regulation skeletal systemsbiology technologyandcivilization troponin twenty-firstcentury