1 The coumarin anticoagulant difenacoum was detected by high performance liquid chromatography (HPLC) with multi-wavelength UV detection in plasma from a 41 year old man who presented with a severe deficiency of vitamin K-dependent clotting factors of unknown aetiology. A longitudinal toxicological study of the consequent coagulopathy is described. 2 Plasma concentrations of difenacoum declined from 0.97 to 0.11 mgl-1 in 47 days with a terminal half life of 11.7 days. Rifampacin (300 mg bd) had no apparent effect on the terminal half life of the drug. Subsequently plasma concentrations of difenacoum and descarbox yprothrombin (DCP) unexpectedly increased. 3 Seven months after exposure clotting times were prolonged. The patient continued to have episodes of epistaxis, haematoma, purpurae and bruising and he required frequent treatment with Fresh Frozen Plasma in additional to oral phylloquinone (200 mg day-1). 4 Intermittent and unexpected increases in plasma concentrations of difenacoum and descarboxypro thrombin suggested that covert, repeated ingestion of the anticoagulant was the most likely cause of the poisoning. The measurement of low concentrations of plasma phylloquinone except following supervised ingestion ofthe vitamin indicated that as an outpatient, the subject was not compliant with treatment despite his protestations to the contrary. He continued to deny this even when confronted by laboratory findings and at no time did he ever admit to self-poisoning.
Self diffusion in f.c.c. cyclohexane crystals has been re-examined using the radiotracer isotope mass effect technique. The experimental penetration curves show that this highly plastic solid is fundamentally very defective. Experiments for short periods yield overall diffusion coefficients dominated by diffusion along dislocations and mosaic boundaries (pipe diffusion) in the lattice. This line defect structure, which is known to increase with impurity content, is believed to be the cause of the very high values of the self diffusion coefficient found previously. The dominance of pipe diffusion was confirmed by isotope mass effect experiments carried out under the previous conditions. These gave values for the mass factor ( f A K ) 2: 0.35 characteristic of pipe diffusion. Careful experiments for longer periods using ultra pure, well annealed, samples yielded values of the mass factor consistent with lattice self diffusion by a vacancy process. For these experiments the self diffusion coefficients and activation energy are in good relative agreement with values found for other rotator phase solids. The activation energy was confirmed by plastic deformation measurements.
Creative problem solving (CPS) is an approach for identifying solutions to problems within a structured, facilitated process. In the current studies, CPS was customized for general education intervention (GEI) teams in elementary schools. In the first study, 24 GEI teams were randomly assigned either to a CPS for GEI training condition or to a control group. Team outcome measures were tracked over the course of a school year, and the CPS for GEI teams consistently demonstrated superior performance relative to controls across all measures. One year later, a second study investigated 2 approaches to delivering training in CPS for GEI teams. Five teams received CPS for GEI training directly from university-based staff, and 9 teams received training from employees in their district who had previously received CPS for GEI training from the university-based staff (a “train-the-trainers” approach). Schools receiving training from their own staff performed as well as the independently trained schools, thereby providing support for the train-the-trainers approach. Discussion focuses on the results from both studies and identifies areas for future research and practice with CPS for GEI teams.
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