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Biomedical subjects

J G Dunn

Publications and source records attributed to J G Dunn.

3 recordsLinked to original sources

Children's self-regulated learning of movement sequences.

The purpose of this study was to determine whether developmental differences exist in childrens' use of self-regulatory strategies while learning supra-memory-span movement sequences. Grade 1 and Grade 4 children were asked to study two movement sequences long enough to be absolutely certain that they would be able to recall the entire sequences correctly. The older group displayed superior recall readiness in comparison to the younger group. Older children used a greater variety of strategies and also displayed significantly greater numbers of strategy orchestration patterns. In addition, Grade 4 children more frequently used overt encoding and self-checking strategies. Further, evidence suggests that Grade 4 children used language to encode movement components or to regulate their own learning more frequently than Grade 1 children.

Age Factors↗

Rapid controlled thawing of fresh-frozen plasma in a modified microwave oven.

A microwave oven has been specifically modified to permit rapid thawing of fresh-frozen plasma (FFP) by using a rotating disc with a temperature sensor to hold the plasma bag. This modification makes it possible to mix the FFP continuously during thawing, and automatically shuts the oven off when the plasma reaches 21 degrees C. Comparisons were made between FFP thawed in the modified microwave oven and FFP thawed conventionally in a 37 degrees C waterbath. The following tests were done: total protein, albumin, and immunoglobulin concentrations; plasma fibrinogen, factor VIII, and factor IX activities; protein electrophoresis, albumin aggregation, hemolytic complement activity, and plasma particle count and size. In no case was there a significant difference between plasma thawed in the microwave oven compared with that thawed in the waterbath. Further, microwave thawing was reliable and rapid; all units of FFP thawed in less than 6 minutes, and the thawed plasma did not vary by more than 6 degrees C from the preselected final temperature of 21 degrees C. Thus, it appears that controlled thawing of FFP in a microwave oven specifically designed for this purpose is an effective and reliable method and has many advantages over conventional thawing of FFP.

Adenine↗