Standard redox potentials, pKas, and hydricities of inorganic complexes under electrochemical conditions and implications for CO2 reduction.

We use computational chemistry to systematically study the thermodynamic stabilities of protonated and reduced intermediate states for Ru(2,2'-bipyridine)3, Ru(1,10-phenanthroline)3, and Ru(phen)2(pyrido[3',4':5,6] pyrazino[2,3-f][1,10]phenanthroline) in aqueous solutions. Following our previous studies of aromatic N-heterocycle molecules, we report pKas, standard redox potentials, and hydricities as well as computationally derived Pourbaix diagrams that show which states would be thermodynamically stable at different conditions of pH and applied potential. Locations of added electrons within ligands and complexes after reductions are also shown with electron density difference plots. As with other aromatic N-heterocycle molecules implicated in CO2 reduction, we find that several of the boundary lines from the Pourbaix diagrams are in close proximity to the thermodynamic redox potentials for CO2 electroreductions, making them thermodynamically appropriate for energetically efficient hydrogen shuttling.

Organochlorines and eggshell thinning in northern gannets (Sula bassanus) from Eastern Canada, 1968-1984.

The northern gannets (Sula bassanus) nesting on Bonaventure Island, Quebec, were studied from 1968 to 1984 in order to measure environmental contaminant levels and their relationship to productivity. Fresh eggs in 1969 contained a mean DDE level of 18.5 mg kg(-1) and had shells which were 17% thinner than pre-1947 samples. Unhatched eggs in 1969 had no outer calcified layer, a mean thickness 20% less than the pre-1947 mean, and mean DDE concentration of 30.6 mg kg(-1). Significantly higher levels of eight contaminants were measured in unhatched than in fresh eggs collected in 1969. DDE and shell thinning were also intercorrelated with nine other contaminants; these data strongly implicate toxic chemicals, particularly DDE, as the main cause for the low breeding success of Bonaventure gannets from 1966 to 1974. Extensive use of DDT to control forest insects around the Gulf of St Lawrence ceased in 1969. Use of DDT, dieldrin and PCBs was restricted in North America during the early 1970s. Residues of DDT, DDD, DDE, PCBs, dieldrin, HCB and chlordane-related compounds in gannet eggs decreased significantly during this study. Heptachlor epoxide remained constant while alpha-HCH appeared to increase. Estimated half-lives ranged from 3.1 years for DDD to 35.4 years for oxychlordane. The breeding success and population of the colony have coincidentally increased.

Developing behavioral science for a family practice residency.

The development of behavioral science in a family practice residency has first to be structured around a statement of purpose and adequate goals. These goals can only be implemented when the purely custodial function of the medical profession is rejected and the ethical responsiblity of the physician to society is allowed to direct the role innovations that must be incorporated. It is the person of the physician as a diagnostic and therapeutic tool that must be cultivated. The curriculum presented has included behavioral science conferences, a one-month behavioral science rotation, a two-month orientation program, behavioral science clinical attendings, and a personal counseling program for each resident throughout the three years of training. To be complete, such a program requires the further refinement of behavioral objectives that allow reliable evaluation and redefinition by residents and faculty.

Characteristics of Successful and Probationary Football Officials.

These researchers suggest that safe, enjoyable football games are more likely to occur with successful officials who are more physically fit, less fat, and psychologically different than probationary officials.