AN ALTERNATIVE APPROACH TO CANONICAL QUANTIZATION FOR INTRODUCING QUANTUM FIELD THEORY: THE DOUBLE-SLIT EXPERIMENT RE-EXAMINED

In the last years a growing research concern, within physics education, has been addressed to the production of teaching proposals for introducing notions of quantum field theories (QFT) at the secondary school level. The proposals are usually the result of the effort of translating the most widespread approach to QFT in university textbooks, \u201ccanonical quantization\u201d, into natural language. After a discussion of the pros and cons of taking canonical quantization as reference, an alternative educational approach is presented. The approach is not yet a teaching proposal but a set of criteria needed for extracting the conceptual and cultural essence of QFT to be taught also without sophisticated formalisms

Ependymitis, Leukoencephalitis, Hydrocephalus, and Thrombotic Vasculitis Following Chronic Infection By Mouse Hepatitis Virus-3 (mhv-3)

Mouse hepatitis virus 3 (MHV 3) is either avirulent (resistant mice), hepatotropic (susceptible mice). or neurotropic (semisusceptible mice), depending on the strain of mice infected. In semisusceptible mice, infection led first to a transient meningitis, ependymitis, and leukoencephalitis, followed by a permanent communicating hydrocephalus and, later on, to a chronic thrombotic vasculitis affecting meningeal and parenchymal vessels at the brain stem level. Small foci of ischemic necrosis related to vascular occlusions were seen in the dorsal brain stem. Cyclophosphamide treatment of semisusceptible mice significantly reduced the meningeal infiltrates but did not prevent the development of hydrocephalus and other neuropathologic changes. Identical lesions occurred in fully susceptible mice infected with a low dose of virus, but no neurologic disorder could be induced in genetically resistant mice even following immunosuppression or intracranial inoculation. The leukoencephalitis differed from the demyelinating lesions observed with MHV4. Vascular lesions were of particular interest. More attention should be given to the possibifity of virus induced chronic cerebral vasculitis in man