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Second order Born approximation of electron-positron elastic potential scattering from extended nuclei is calculated, and a general formula is given for any charge distribution. The dependence of (σ−−σ+)/σ− from particular charge distributions is analysed and discussed.

The contribution of the soft photons to the high-energy electrodynamical cross-sections is investigated. In particular we discuss the appearing of α ln2 (E/m) terms in the perturbative expansion. Particular cases are considered.

By saturation of equal-time commutators of current algebra and field algebra, expressions for physical electroproduction amplitudes are deduced. They contain electromagnetic and axial form factors plus terms of orderμ2 (pion mass). A detailed evaluation of those corrections 3 is discussed together with the comparison with experiments.

Using a dispersive representation for the equal-time commutators of theSU2⊗SU2 algebra we get a sum rule for the axial vector form factorG(Δ2), which can be expressed in terms of the vector form factorF1V(Δ2) and of the imaginary part of the electroproduction amplitude.

The form factors of the N33∗N weak axial vertex are expressed in terms of the form factors of the nucleon. A relation between N33∗Nπ and NNπ coupling constants and an estimate of the mass of a 1+ meson are obtained.

The question of whether mu + mu /sup -/ pair production in e+eannihilation can be used to test quantai electrodynamics (BED) at short distances is examined. The cross section ratio, sigma / sigma /sub 0/, is shown to be dependent on the angle if, in the equation for sigma ( theta ), DELTA is not zero, and hence the mu /sup +/ mu /sup -/ pair production can be used to test QED at distances of the order of 10/sup -14/ cm. (D.L.C.)

The total cross section to e/sup 6/ is calculated for annihilation of an electron-positron pair into photons. Comparison with experiments at CERN is discussed and some consideration about the behavior of cross section for electrodynamical processes at high energy is outlined. Some details of calculation are sketched in an appendix. (auth)

We study classical solutions of the meron type in the framework of N = 3 and N = 4 extended supergravity.

BS>The electroproduction of schizons is studied as a process which presents a favorable situation for answering the problem of the existence of an intermediate boson field as a transmitter of the weak interactions. (T.R.H.)

Ventricular aneurysm is a frequent complication of myocardial infarction, but its diagnostic and prognostic implications are not fully defined. A surgical series of 66 ventricular resections for symptomatic left ventricular aneurysm is analyzed. Pts. age varied between 26-29 years; the interval between the episode of infarction and operation from 2 mos. to 12 years. Indication for surgery was angina in 53% of the cases, heart failure in 23%, arrhythmias in 15%, angina and failure in 9%. In 55 cases surgical findings were consistent with true aneurysm in the anatomical sense, in 11 cases with a wide area of wall akinesia. In 24 cases endocavitary thrombosis was present. In 23 cases aneurysmectomy was the only surgical procedure, with closure of acquired VSD in 1 case and mitral valve prosthesis in 2 cases. In 43 cases aorto-coronary bypass grafting was associated (single bypass in 18, double in 23, triple in 2). Operative technique underwent modifications in time, in relation to the use of local and general hypothermia, of cardioplegia, of early aortic cross-clamping. Surgical mortality was of 7.5% (5 cases); the actuarial courve, including operative mortality, showed survival of 88% at 1 year and of 78% at 5 years interval. Correlation between mortality and clinical symptomatology, hemodynamic data and surgical findings was not statistically significant; a statistically highly significant correlation was found between mortality and operative technique. The results are interpreted and discussed in relation to the diagnostic definition of the problem, to the criteria of indication to surgery and to the operative technique.

During the period 1966-1977, 705 pacemaker implantations with transvenous endocardial electrode and 369 substitutions of generators were carried out, besides 275 operations treating some complications after implantation were required. The most frequent complications were: endocardial electrode dislocation (9.4%), lesion caused by decubitus (7.5%) and infection of subcutaneous pocket (5%), decubitus lesion and infection of the skin caused by the electrode (1.7%), electrode and generator breaking (1.3%), right ventricle perforation caused by the electrode (0.37%). Surgical mortality-rate was 0.18%.

We offer a systematic treatment of the connection between stochastic quantization and supersymmetry. This is done in the original Nicolai-Parisi-Sourlas approach and by use of the “stochastic identities” which can be derived as a consequence of the supersymmetry invariance both of the action and of the vacuum. We deal extensively with the cases of quantum mechanics, scalar field theory and gauge theory. One of the main results is the presence of a reduced set of stochastic identities even when a local Nicolai transformation does not exist.

The properties of a field theory in one over-all time dimension, invariant under the full conformal group, are studied in detail. A compact operator, which is not the Hamiltonian, is diagonalized and used to solve the problem of motion, providing a discrete spectrum and normalizable eigenstates. The role of the physical parameters present in the model is discussed, mainly in connection with a semi-classical approximation.

The correspondence between stochastic quantization and supersymmetry is extended to N =1 gauge supersymmetry coupled with matter. This applies to N =2 extended gauge supersymmetry and also to N =1 SUSY in six dimensions. The special role of the light plane gauge is emphasized.

A case of primary ependymoma of the mediastinum is reported. The tumor was adherent to the lung and metastasized to adjacent mediastinal lymph nodes. An autopsy showed no evidence of tumor in the central nervous system. The diagnosis of ependymoma was confirmed by the immunohistochemical positivity for glialfibrillary acidic protein. To the best of our knowledge, this is the first reported example of an ependymoma in this location.

The correspondence between stochastic quantization and supersymmetry is reobtained for the quantum mechanics case by use of “stochastic identities”. The method is easily generalized to N =1 super Yang-Mills theory in the light cone gauge.

Cefonicid pharmacokinetics in serum and tissue penetration into the lung parenchyma, bronchial mucosa and pleura were studied in 39 patients undergoing lung excision for malignancy. Cefonicid concentrations in serum and tissues samples were assayed at different times after a single 1 g intramuscular administration. The concentrations observed were much higher than the reported minimal inhibitory concentrations for the microorganisms commonly responsible for bronchial and pulmonary infections and therapeutic concentrations were still detectable in the tissues 24 h after dosing. Kinetic findings demonstrated a similar half-life for cefonicid in tissues and in serum. These data provided a further kinetic explanation for the observed clinical efficacy of cefonicid with a single daily dose.

We present a preliminary discussion of some consequences of a fully dilatational invariant formulation of the Einstein theory of gravitation. Arguments are given to show that the small distance behaviour of the theory can be greatly improved, leading to a situation very similar to usual renormalizable theories.

The authors discuss in detail the classical solutions of two field theoretical models invariant under general variable transformations. In particular they examine the case of a Yang-Mills theory and of a four-dimensional nonlinear sigma model, both coupled to 'strong gravitation'. Instanton, meron and multimeron configurations are obtained and their properties discussed. (25 refs).

We discuss the role of the Newton constant in gravity theory. We show that the natural way to deal with the general covariance of the theory is to notice that the action is independent of any dimensional constant. The Newton constant is introduced in gravity through the classical constant solutionγμν=(1/l2)δμν which displays the dilatation breaking of this Poincare invariant solution. Nothing changes for the usual results of classical gravity since the Newton constant is responsible for the low-energy limit. However, it is easy to realize that there are other solutions of gravity coupled to matter (Yang-Mills and sigma-model) where both fields have the same intensity and the Newton constant does not appear. These «non-Newtonian» solutions are due to the specific nonlinear character of general gravitation. They can be relevant to the hadron structure. The above observations give a hint that the asymptotically small-distance behaviour of the gravity theory is independent of Newton's constant and should reflect the general invariance of the theory, provided that infinite classes of quantum diagrams are summed up.

In the last two decades improvements in immunosuppression, surgical technique and graft preservation has impressively enhanced transplantation late results. In the present paper we wonder whether this surgical procedure has a role in the treatment of patients with end-stage respiratory disease as cystic fibrosis (CF). We also try to relate on the main clinical, histological development, present status and the real therapeutic value of cardiopulmonary and double-lung transplantation for end-stage CF. We believe lung transplant may well extend the patient life and give a better quality of life to CF patients who would otherwise die, although functional time is presently unknown. Next years challenge ought to be to go critically through clinical results, to focus on existing problems, together with developing appropriate solutions so to allow a better surgical indication of pulmonary transplantation.

Air-lead levels (PbA) and biological indices were studied in three ceramic factories (185 workers altogether). A difference in the pattern of lead exposure was found in the largest factory (A) and the other two smaller factories (B and C). PbA never exceeded 67 micrograms/m3 in factory A, but reached values as high as 378 micrograms/m3 in factory B. 19% of PbB values were higher than 40 micrograms/100 ml in factory A, 63% in factory B and 35% in factory C. As was expected, a closer analysis of the jobs confirmed a higher exposure level in people directly in contact with lead glazes (glazers and kiln operators). In factories B and C, however, there was also a significant lead uptake in selection and maintenance staff, who worked in areas at some distance from the glazing lines. This may be due in part to pollution spread over all departments, but also to the lack of hygiene and washing facilities whose importance is stressed for effective prevention. Biological monitoring is suggested as being useful for all workers, whatever the lead-air level, bearing in mind the possibility of lead intake orally through soiling.

Gravitation is the oldest of the fundamental interactions known to us. It finds an extraordinarily beautiful and simple formulation in Einstein’s General Relativitiy, which embodies the equivalence principle by requiring the invariance of the theory under general reparametrization of the co-ordinates xμ → x′μ = fμ(x). Experiments confirm the predictions of the classical theory in the macroscopic, large distance, domain.

We discuss, both in potential scattering and in quantum field theory, the connection between the bound state problem and the renormalizability of the theory. In particular, it is shown that a meaning can be given to the bound-state condition also in the framework of perturbation theory, also if all the terms of the series are cut-off-dependent.

We study the solutions of the Bethe-Salpeter equation for bound states, in the ladder approximation, in the case of potentials both regular and singular near the origin. Two methods are presented, one in momentum space, the other in co-ordinate space, which allow the complete determination of eigenvalues and eigenfunctions, in the case where both the total energyE of the state and the mass of the exchanged particle are zero.

A new relativistic approach to the problem of broken symmetries is proposed. This is the covariant generalization of the non-relativistic sum rules obtained in previous investigations. The result is in the form of dispersion sum rules where the pole term represents the group-theoretical answer and the cut the breaking correction. The method is applied toSU3 and chiralSU3×SU3 leading to very satisfactory results and predictions.

We study the short-wavelength approximation to the Schrodinger equation in the presence of one and two turning points. Two methods are presented which allow the evaluation of the higher corrections to the elementary W.K.B. approximation. The first method, the « real method », employs higher transcendental functions, the second one uses complex integration techniques.

A general method for calculating the renormalization of partially conserved vector currents due to symmetry breaking is discussed. As an application, the renormalization of the strangeness-changing weak vector current is calculated in the pole approximation and its effect on universality is discussed.

A fruitful advance in our understanding elementary particle physics has been achieved through current algebras [1]. This approach is characterized first of all by the choice of currents as fundamental quantities in describing the weak and electromagnetic interactions of hadrons. Then a very attractive suggestion follows in order to establish a bridge between the observable hadron currents and symmetry operators of the theory: according to Gell-Mann we identify the charges (associated to those vector and axial vector currents) with the generators of the SU(3) × SU(3) group *.

The validity of the renormalization group equations used to obtain Regge pole behavior is discussed. It is shown that the renormalization group equations contain a certain amount of arbitrariness when a perturbation theory amplitude is used as input. (C.E.S.)