A wide spectrum of resistance to pyrethroid insecticides inMusca domestica

Summary Selection of a strain of house flies with the pyrethroid bioresmethrin has resulted in a wide range of cross resistance to 15 other pyrethroid insecticides.     

Phospholipid composition ofDipylidium caninum

Summary The phospholipid composition ofDipylidium caninum has been studied. Chloroform-methanol-soluble fraction amounted to 2.4% and phospholipids to 0.5% of the wet weight of the parasite. Phosphatidyl choline and phosphatidyl ethanolamine represented the bulk of the phospholipids, whereas phosphatidyl serine, phosphatidyl inositol, lysolecithin and lysophosphatidyl ethanolamine were present in minor amounts. Sulfatides were also identified in this parasite.     

Effect of light adaptation on electrical responses of the retinas of four species of bats.

The levels of light adaptation at which the retinas of 4 species of microchiropteran bats became unable to generate electroretinograms were progressively ordered. The order correlated well with light preferences based on activity patterns of the 4 species. These results suggest that the ability of the retina to function in ambient light may govern some natural behaviors of these bats.     

The control of contraction activation by the membrane potential

Summary Force measurements under voltage-clamp control were performed in short toe muscles of the frog. The results show a) that the activation of force development and its repriming process can at least qualitatively be correlated to charge movement kinetics; b) that caffeine improves EC coupling by potentiating the potential dependent activation process.This work was supported by DFG (SFB 114 Bionach) and DAAD.     

Molekulargewichtsbestimmung von Kalbsherzmyosin

Summary Sedimentation and diffusion coefficients, partial specific volume, intrinsic viscosity, ATP-ase activity and molecular weight of cardiac myosin from calf hearts were determined. The values agree well with the results ofMueller et al.⁴ for cardiac myosin of the dog, and are not essentially different from values reported for skeletal myosins.¹