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The authors investigated the perceived relationship between spelling errors and cognitive abilities in a series of 3 experiments. Specifically, they examined whether college students' ratings of an author's intellectual ability, logical ability, and writing ability were affected by the presence of spelling errors. In the 1st experiment, the presence of 4 spelling errors in a short essay did not significantly affect the ratings. The spelling ability of college students, as measured by a standard oral dictation spelling test, was moderately conelated with a brief test of intelligence. In a 2nd experiment, college students rated the author of a short essay as having lower ability when there was a large number of spelling errors. The effect was more pronounced on the ratings of writing ability than it was on the ratings of logical ability or intellectual ability. This finding was replicated in a 3rd experiment, in which the essay contained misspellings actually made by writers. The results suggest that spelling errors can affect how people perceive writers, particularly when there are many spelling errors. College students appear to attribute spelling errors more to writing ability than they do to general cognitive abilities such as intelligence and logical ability.

In 1990 and 1991, populations of the cabbage aphid, Brevicoryne brassicae, and the green peach aphid, Myzus persicae, were monitored on broccoli interplanted with three leguminous cover crops (the living mulches) and compared with broccoli without cover crop (clean cultivation). The cover crops used were white clover ( Trifolium repens L.), strawberry clover (Trifolium fragiferum L.) and a mixture of birdsfoot trefoil (Lotus corniculatus L. ) and red clover (Trifolium praetense L.). Fertilizer was applied as compost or synthetic fertilizer crossed with cropping system regime. Brevicoryne brassicae can reach pest status in Brassica cropping systems, whereas M. persicae is generally innocuous. Both aphids are attacked by the parasitoid Diaeretiella rapae. Seasonal aphid abundance, parasitism and population growth rates were analyzed.No significant effect of fertilizer was found for any of the parameters analyzed. The living mulches had lower aphid populations overall, although differences with clean cultivation were greatest early in the season for M. persicae and diminished over time. No effect of cropping system on population growth rate was seen for Brevico ryne brassicae, but for M. persicae growth rates were higher in living mulches compared with clean cultivation. Parasitism was highest on clean cultivated broccoli for both aphid species in 1990 and for M. persicae in 1991, but no differences were found for Brevicoryne brassicae in 1991. This suggests that differential population growth rates and parasitism seen for M. persicae are a result of inhibition of D. rapae in the living mulches. Possible reasons for differences in parasitism between the two aphid species in living mulches and clean cultivation are discussed.

Abstract. 1. Cover crops and/or resident ground vegetation have been used in California vineyards to increase the number of predators and decrease the number of pestiferous herbivores. The most common resident predators in vineyards are spiders (Araneae). Several observational studies suggest that the addition of cover crops results in an increase in spider density and a decrease in insect pest densities.2. To test experimentally the effects of cover crops and/or resident ground vegetation (hereafter collectively referred to as ground cover) on spider populations, a 3-year study was undertaken in a commercial vineyard. Large, replicated plots were established with and without ground cover during the growing season. Spider species diversity was analysed on the vines and on the ground cover.3. On the vines, there was no significant difference in spider species richness or the total number of spiders in plots with and without ground cover. There were differences in the relative abundance of two spiders between treatments, with one species (Trachelas pacificus [Chamberlin & Ivie]) more abundant in plots with ground cover and another (Hololena nedra Chamberlin & Ivie) more common on vines in plots with no ground cover. Annual variation in spider abundance was greater than variation due to ground cover treatment.4. On the ground cover, the spider species diversity was considerably different from that found on the vines above, suggesting that there is little movement of spiders between the ground cover and the vines. Enhancement of T. pacificus populations on vines with ground covers may be a result of prey species movement between the ground cover and the vines. Spider abundance was sparse on the bare ground.5. The maintenance of ground cover increased spider species diversity in the vineyard as a whole (vine and ground cover). However, the relatively small changes in spider abundance on the vines indicate there are limitations in the use of ground covers for pest management with respect to generalist predators.

The alpha-1 acid glycoprotein (orosomucoid; AAG) is a normal constituent of human plasma (650+/-215 microgram ml(-1)) which increases in concentration as much as fivefold in associations with acute inflammation and cancer, and thus is recognized as an acute phase protein. AAG consists of a single polypeptide chain, has a molecular weight of 44,100, and contains approximately 45% carbohydrate including 12% sialic acid; it is the most negatively charged of the plasma proteins. Certain of the biological properties of AAG are related to its sialic acid content; thus, clearance and immunogenicity of AAG are markedly increased on desialisation. The biological functions of AAG are largely unknown. AAG has the ability to inhibit certain lymphocyte re-activities including blastogenesis in response to concanavalin A, phytohaemagglutinin and allogeneic cells, and these inhibitory effects are enhanced in association with desialisation. In view of these observations, a report that unphysiologically large (5--15 mg ml(-1)) amounts of AAG inhibit the platelet aggregation induced by ADP and adrenaline, and evidence that a sialic acid-deficient species of AAG appears elevated in several chronic disease states, we compared the effects of AAG and its desialised counterpart (AAG-D) on platelet aggregation. We report that desialisation of AAG is associated with increased expression of activity inhibitory to the platelet aggregation otherwise observed on stimulation with ADP, collagen or thrombin.