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D Johannessen

Publications and source records attributed to D Johannessen.

3 recordsLinked to original sources

Uranium series isotopes in the Avon Valley, Nova Scotia.

An U-series isotopic study was carried out in the waters of the Avon Valley, Nova Scotia. The fresh and acidic recharge waters flow rapidly through the watershed composed of a granitic highland and a sedimentary, largely carbonate, lowland plain, before draining to the sea. There is no significant anthropogenic pollution; but, naturally elevated U levels can be encountered within the bedrock. Nonetheless, the U concentrations of the surface and groundwater are low (generally within the range of several hundredths to several tenths of a microg l(-1)), except in the proximity to weathering of U mineralization. The dissolved U in the surface waters appears to be stabilized by organic rather than inorganic complexes. Both the groundwaters and surface waters have similar (234)U/(238)U activity ratios that rarely deviate from secular equilibrium by more than 20% throughout the watershed. The magnitude of the (234)U/(238)U activity ratio is not determined by lithology but rather by the weathering mechanism, the high rate of flushing, and the leaching of local U mineralization. Dissolved Ra is consistently absent. The dissolved Rn concentrations, though variable, are measurable even in surface waters. This may be due to a continual degassing from the U-enriched bedrock or release from local sites of U mineralization underlying the surface water sources.

Environmental Monitoring↗

Response to sodium lactate infusion in alcoholics with panic attacks.

The authors studied the response to sodium lactate infusion of 12 alcoholics with a history of panic attacks, 10 alcoholics without a history of panic attacks, and 16 nonalcoholic patients with panic disorder. The rate of lactate-induced panic was significantly higher in alcoholics with panic attacks than in alcoholics without panic attacks. Alcoholics with panic attacks were similar to nonalcoholic patients with panic disorder in their response to lactate. These findings support the specificity of lactate-induced panic for panic states and suggest that panic attacks in alcoholics resemble those in nonalcoholics. Lactate infusion may prove useful in the diagnosis of panic disorder in alcoholics.

Adult↗

Low plasma fibronectin after drowning.

The plasma concentrations of fibronectin were zero for 8 days in a 53-year-old male who was submersed for 5 min, but conscious at the time of admission to hospital. The patient developed multiple organ failure, disseminated intravascular coagulation and finally died after 15 days. The low fibronectin values indicate prolonged severe reticulo-endothelial failure, and may be a prognostic sign in cases of drowning or asphyxia of other etiologies.

Combined Modality Therapy↗