The post-collision interaction (PCI) is investigated in Auger processes induced by electron impact ionization. (An Auger decay of an inner vacancy results in the creation of four charged particles in the final state of such a process.) General formulae allowing for PCI are obtained for energy and angular distributions of the Auger electrons. The expressions obtained beyond the eikonal approximation describe the Auger spectra measured in coincidence and nonaincidence experiments. Results of our approach are applied to the case of the AI LI-M2,M2~ Auger spectrum following electron impact ionization. The calculations show the essential PCI distortion of the lineshape and the angular distribution in coincidence measurements; in noncoincidence experiments only the lineshape is disturbed, not the angular distribution. Our results do not show the low-energy structure of the Auger line measured in coincidence with the scattered electrons.

Abstract.-DNA isolated from skin epitheliomas containing papovavirus induced lymphomas within four to eight weeks in 40 to 50 per cent of newborn Syrian hamsters injected. This DNA effect was eliminated by DNase but not by RNase and was not induced by DNA preparations of transplanted epitheliomas or the induced lymphomas. Lymphomas were similarly induced by cellfree filtrates from certain human tumors such as gastric carcinomas and ovarian tumors. Little or no lymphoma effects were observed following injections with filtrates derived from normal human or animal tissues or human blood. The lymphomas induced by DNA and human tumors were transmissible by cell-free filtrates to newborn Syrian hamsters; however, successful serial passage, like the primary lymphomas induced by the DNA preparations, depended upon the use of a newborn hamster from a special breeding colony of hamsters.Introduction.-In previous publications, we reported both the spontaneous incidence of multiple skin epitheliomas (papillomas) containing large numbers of papovaviruses in Syrian hamsters1 and an associated induction of leukemias, predominantly lymphomas.2 The latter originated in almost every case in the liver of Syrian hamsters which as newborns had been treated with cell-free filtrates from the hamster skin tumors. The hamster lymphomas, which were separately transmissible by cell-free extract, contained a virus with the morphology of the C-type murine leukemia virus; interestingly, the papovavirus present in skin tumors could not be detected in the lymphomas by electron microscopic examination. Herewith, we report additional results concerning especially the induction of hamster lymphomas by DNA from spontaneous skin epitheliomas containing papovavirus. In addition, experiments are briefly described in which the lymphomas also appeared in significant numbers after subcutaneous inoculation of hamsters with filtrates derived from certain human tumors.Materials and Methods.-DNA was isolated from tissues of primary skin epitheliomas containing papovavirus. The tissue was either freshly excised or frozen at -80'C. The

The mass spectra of three bicyclic y-lactones have been studied, and the fragmentation pathways have been proposed with the aid of accurate mass measurements and metastable transitions. An unusually low [M -CH,] ion and the presence of an abundant [M -C,H,] ion in the mass spectrum of dihydroactinidiolide u ere interpreted as a possible rearrangement involving a methyl migration. The eliminations of methyl radical, carbon monoxide and ketene are important processes in many cases.

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We measured the lineshapes of Ne K-L2,3L2,3 and Ar L2,3-M2,3M2,3 Auger electrons distorted by post-collision interaction (PCI) for electron-impact ionization. The excess energies E1 = E0-I(nlj) (E0 and I(nlj) are the incident and the ionization energies) were 27-427 eV for Ne K ionization and 12-750 eV for Ar L3 ionization. For comparison we calculated theoretical Auger spectra where the PCI-distorted lineshape, obtained in eikonal theory (Sheinerman et al 1994 J. Phys. B: At. Mol. Opt. Phys. 27 5681), was convolved with the experimentally known spectrometer function and a Gaussian function for the Doppler effect of the thermally moving target atoms. The agreement of experimental and theoretical spectra is excellent in all cases. This demonstrates the quality of eikonal theory in calculating the PCI-distorted Auger lineshapes.