Design of a computerized device to measure simple reaction time/decision time

The construction and validation of a computerized device to test simple reaction time and decision-making time is discussed. The device is required to demonstrate repeatability (consistency of response times from human subjects) across replications of the same experimental condition. A second requirement of the device is that it must separately and independently measure simple reaction time and the time it takes to process one bit of information. The concepts behind the construction of the box are discussed, as well as the design of its internal circuits to achieve these specifications.

Laser flow cytofluorometric analysis of HTC cells synchronized with hydroxyurea, nocodazole and aphidicolin

The technique of laser flow cytofluorometry has been used to monitor the arrival in G1 and the subsequent progression through the cell cycle of HTC cells accumulated in metaphase with colcemid alone or after treatment with hydroxyurea and Nocodazole. Under the experimental conditions used in this study, the latter procedure gives much better results, avoiding in particular the extensive formation of micronucleated cells. Aphidicolin, an inhibitor of DNA polymerase, in combination with Nocodazole, provides a useful method to tightly synchronize these cells at the G1/S border.

Vaccinia virus: the possibilities of its oncogenicity in humans

Contrary to the earlier generally accepted view that vaccinia virus replicates in the cytoplasm only of suitable target cells, steadily accumulating data show that the viral genome spends a limited period of time in the nucleus. This, together with the many cases where a close association has been suspected or established between skin cancer and vaccination, suggests that vaccinia virus may, under certain yet undefined physiological conditions, act as an oncogenic virus in humans.