Prion diseases are fatal, chronic neurodegenerative diseases of mammals, characterized by amyloid deposition, astrogliosis, microglial activation, tissue vacuolation and neuronal loss. In the ME7 model of prion disease in the C57BL/6 J mouse, we have shown previously that these animals display behavioural changes that indicate the onset of neuronal dysfunction. The current study examines the neuropathological correlates of these early behavioural changes. After injection of ME7-infected homogenate into the dorsal hippocampus, we found statistically significant impairment of burrowing, nesting and glucose consumption, and increased open field activity at 13 weeks. At this time, microglia activation and PrPSc deposition was visible selectively throughout the limbic system, including the hippocampus, entorhinal cortex, medial and lateral septum, mamillary bodies, dorsal thalamus and, to a lesser degree, in regions of the brainstem. No increase in apoptosis or neuronal cell loss was detectable at this time, while in animals at 19 weeks postinjection there was 40% neuronal loss from CA1. There was a statistically significant reduction in synaptophysin staining in the stratum radiatum of the CA1 at 13 weeks indicating loss of presynaptic terminals. Damage to the dorsal hippocampus is known to disrupt burrowing and nesting behaviour. We have demonstrated a neuropathological correlate of an early behavioural deficit in prion disease and suggest that this should allow insights into the first steps of the neuropathogenesis of prion diseases.

SYNOPSIS.2. HISTORICAL. a) THE PRECIPITIN REACTION AND VEGETABLE PROTAINS.Kowarski' seems to have been the first to report (July 4, 1901) the observation of precipitins for vegetable proteins. He immunized rabbits with solutions of noncoagulable proteins from wheat flour, and obtained a precipitin for a saline extract of wheat flour. The immune serum also gave a distinct, but less heavy precipitate with extracts of the seeds of peas, rye, and barley, but not with an extract of the seeds of oats. From his observations he suspected that the specificity of vegetable proteins

No abstract

Word prediction is often recommended by therapists as a means to improve typing speed for clients with physical limitations. Although literature suggests that word prediction does have an effect on writing proficiency, increased speed is not one of its benefits when used with a standard keyboard. One reason given for the failure of word prediction to accelerate typing is that the user must look away from any source document to scan the prediction list during typing. Looking away from the source document may slow the typist more than any acceleration offered by word prediction. For input methods that already require the typist to look away from the copy, this effect might be irrelevant. The focus of this research was to determine whether word completion or word prediction programs would increase typing speed when used with an input method (an on-screen keyboard) that also requires looking away from the source document. Ten people, five men and five women, aged 20 to 38 years, participated in this study. The study used a single-subject, successive intervention design to test typing speed and accuracy using an on-screen keyboard with integrated word prediction software. Seven participants had their fastest typing speed with word prediction. Two participants had their fastest typing speed with word completion. Only one participant demonstrated no improvement in speed when using these two programs. Overall, these results show that the use of word prediction and word completion may assist on-screen keyboard users to improve typing speed.