Iowa State Journal of Research 53.4

von Wittich, B. Mastery learning, the efficient approach to foreign language acquisition. 243 Sivakumar, M.V.K., and R.H. Shaw. Attenuation of radiation in moisture-stressed and unstressed soybeans. 251 Hatfield, J.L., and R.E. Carlson. Leaf-water potential patterns within two soybean cultivars. 259 Atkins, R.E. Yield comparisons among short-stature seed parents of grain sorghum. 269 Miller, I.L., and .E. Atkins. Comparisons of embryo weight and seedling growth in grain soghum parents and hybrids. 273 Stinker, Jr., F.M. Acceptance of social accounting: a Guttman scale analysis. 283 Mock, J.J. Investigation of genotype x environment interaction for cold tolerance of maize. 291 Slavik, M., W. Schuller, and W.P. Switzer. Immunization of swine with Mycoplasma hyopneumoniae vaccines. 297 Petersen, M.K. A laboratory test of species exclusion in Sigmodon fulviventer and S. hispidus. 301 Williams. D.D. Seasonal incidence of Isoglaridacris wisconsinensis (Cestoda: Caryophyllaeidae) in its fish host. 305 Williams, D.D. Seasonal incidence of Glaridacis laruei and G. catostomi in Red Cedar Rive, Wisconsin Catostomus commersoni. 311 Witkowski, J.F., and J.C. Owens. Corn rootworm behavior in response to rap corn.. 317 Weller, M.W. Small-mammal populations and experimental burning of Dewey\u27s Pasture, Northwest Iowa, 1970-74. 32