Self assembly of the ditopic ligand L1 with Cu2+ gives the dinuclear double helicate [Cu2(L1)2]4+, which can further coordinate s-block cations. This coordination alters the helicate pitch to a variety of different lengths depending on the size and charge of the guest cation.

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In all three countries, the adoption of participatory policies by govern ments can be traced back to certain aspects of post-war capitalist de velopment - concentration, structural change and, concomitantly, an extensive increase in state intervention. More directly, the introduction of participatory policies in the U.S. during the 1960's is interpreted as a partisan strategy in response to social stress, and is linked to the particular forms of local politics. In Britain, planning participation was perhaps more a result of development bottlenecks and informational needs of govern ment. The comparatively weak impact of citizen participation concepts on governmental policies in Sweden is explained by differences in the forms of local politics and by the relatively less severe nature of social stress and conflicts in urban development.

Measurement of the beat of the semi-isolated cockroach heart, by impedance conversion, showed that the whole abdominal heart of large nymphs or adults responded to low concentrations of acetylcholine (ACh) or 5-hydroxytryptamine (5-HT) by increasing the rate of heartbeat. Preparations, which included 2-chamber sections of the abdominal heart, showed vastly reduced responses to ACh compared to the responses of the whole abdominal heart. Responses to 5-HT were similar in both preparations. Following assay with 5-HT, the cockroach heartbeat often developed marked regularity. ACh assays produced such regularity only rarely. The sectioned cockroach heart preparation was decreasingly responsive to 5-HT > synephrine > octopamine > tryptamine > dopamine > tyramine. Dose-response curves revealed that the antagonist 501 c interacted competitively with 5-HT on the cockroach heart preparation. 501 c appeared to be a non-competitive antagonist to octopamine, suggesting that 5-HT and octopamine act at separate receptor sites on the myocardium. Experiments in which solutions of dibutyryl cyclic AMP, dibutyryl cyclic GMP, or aminophylline were continuously perfused on the cockroach heart, failed to establish that cyclic nucleotides mediate neurotransmitter or hormone action on this tissue. Cockroach hearts were not responsive to prostaglandin E1, F1, picrotoxin, L-glutamate, or ATP below 10−3-10−4M doses.