1994j-841 biological chemicalwarfare dietaryservices ernährung foodpreservation hirnfunktion history kognition military militaryhygiene militarymedicine militarypersonnel nutrition nutritionalaspects nutritionalphysiologicalphenomena nutritionalrequirements operationalrations(militarysupplies) physiological soldat soldiers stress stress(physiology) taskperformanceandanalysis unitedstates