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Attempt is made in this paper to calculate the synthesis probability of the superheavy nucleus with atomic number 120 and compare our findings to the results obtained by other researchers. Our findings include important parameters such as the survival probability of the residue nucleus and the fission barrier height, leading to determination of the evaporation residue cross section. The fission barrier height of the nucleus with Z= 120 is calculated by a revised relation and then compared to the neutron separation energy. It is shown that the production probability of our superheavy nucleus with Z= 120 and A= 296 is higher as compared to its other isotopes, but the fission barrier height of the superheavy element 120 with mass number 299 is higher than other isotopes. The hot fusion reaction 50Ti + 249–251Cf is suggested for such synthesis.

Presents several letters to the editor referencing articles and topics discussed in previous issues. "Trade Rout," published in the January 14 issue; Political problems faced by Argentina; "Successor Story," published in the January 14 issue; Struggle of Iranian Crown Prince Reza Pahiavi to bring democracy to Iran; "Modest Proposal" published in the January 14 issue; Judicial philosophy of Justice Stephen Breyer.

1. The present studies are designed to determine whether a ouabain-sensitive inhibitor of Na+, K+−stimulated ATPase is released into the circulation when the Na+ levels are elevated in the cerebral ventricles in pentobarbital anaesthetized dogs. Na+−pump activity was estimated in the plantar and dorsal branches of the lateral saphenous veins by using the 86Rb-uptake method. 2. Infusion of the cerebral ventricles with the artificial cerebrospinal fluid (CSF) containing normal Na+ (0.15 mol/l) for over 120 min resulted in significant increases in only ouabain-sensitive 86Rb-uptake. In contrast, when the ventricles were perfused with the CSF containing high Na+ (0.3 mol/l) for similar periods, there were significant reductions in the ouabain-sensitive as well as in ouabain-insensitive 86Rb-uptake by the blood vessels. 3. Similar blood vessels from a separate group of dogs were incubated for 120 min in the plasma samples collected from the above groups in which normal or hypertonic Na+ solutions were infused. The data showed that ouabain-sensitive 86Rb-uptake (but not the insensitive component) was significantly inhibited only in those vessels which were incubated in the plasma samples that were obtained at 120 min after perfusion of the cerebral ventricles with CSF containing high Na+ (0.3 mol/l). 4. These studies have provided direct evidence which would suggest that the elevation of Na+ levels in the cerebral ventricles would precipitate the release of an inhibitor of the ouabain-sensitive Na+−pump into the circulation, perhaps due to an activation of Na+−sensitive and/or osmo-sensitive sites in the circumventricular organs. It is hypothesized that this humoral substance may be the same ‘natriuretic hormone’ which is released after acute expansion of circulating blood volume.