壳聚糖对力竭运动小鼠红细胞膜脂质过氧化水平及ATP酶活性的影响

目的:补充壳聚糖6周,观察力竭游泳后,卜鼠红细胞膜脂质过氧化水平及ATP酶活性的变化,探讨壳聚糖保护红细胞膜、提高机体抗疲劳能力的作用.方法:KM小鼠随机分为安静组、力竭组、药物组.药物组灌服壳聚糖6周后与力竭组进行力竭游泳实验,记录游泳至力竭时间,并测定红细胞膜MDA含量、SOD、GPH-Px、ATP酶的活性.结果:小鼠力竭游泳后红细胞膜MDA含量显著升高,SOD活性显著下降,ATP酶的活性下降;而药物组力竭运动后红细胞膜MDA含量显著低于力竭组,SOD及ATP酶的活性显著高于力竭组,GSH-Px活性与力竭组相比有升高趋势但没有统计学意义;补充壳聚糖可延长小鼠游泳至力竭时间.结论:补充壳聚糖能明显减缓力竭运动导致的红细胞膜脂质过氧化损伤程度,维持红细胞膜ATP酶的活性.     

Was Humpty Dumpty Right? An Exploratory Study of Semantic Priming and Lexical Access

This study investigates the way subjects gain access to their internal lexicon and assesses the effects of context on this process. The focus is on ambiguous words that are homographic but pronounced differently. A total of 35 adult subjects read aloud from word lists containing the same target homographs. In two conditions the targets were primed by words calculated to influence subjects either towards a regular or irregular pronunciation; a third condition without primers provided a baseline check. The influence of primers on subjects’ pronunciations was recorded and calculated. Results confirmed a significant influence of primers on pronunciation for a majority of target words. Further analysis showed groups of subjects were significantly (p<0.001) influenced by semantic primers. However, results are interpreted cautiously and proposals are made for a more rigorous study using this exploratory work as a basis. Finally, the potential of semantic priming studies for future research is outlined.     

Spelling errors as a window on variations in phonological deficits among students with dyslexia

Characteristics of spelling development and spelling error patterns were examined in 100 schoolchildren (aged 7 to 15 years) previously identified as dyslexic with specific phonological weaknesses. Within a severely restricted range, spelling development generally followed a normal course despite wide individual variation. The group was divided using two different spelling criteria: (1) global spelling stage, and (2) a split based on the number of spelling confusions involving phonetically similar consonants. Comparisons using either criterion led to the conclusion that better spellers are also better readers and are more skilled in phoneme manipulation. Regression analyses suggested that measures of phonemic segmenting and manipulation make independent contributions to the acquisition of word reading. Phoneme segmenting explained significant variance only when students were subdivided according to errors in coding confusable consonants. Implications for instruction are considered.     

Reading and Comprehension: a longitudinal study of ex‐Reading Recovery students

The paper reports the results of a longitudinal case study conducted in Australia and New Zealand. The study compares the reading and comprehension age of children in their fifth and sixth years in school. Reading and comprehension ages of 121 children who had Reading Recovery intervention at age 6 were compared with those of a Comparison group of 121 children, drawn from the same classes who, at age 6 years, had been better performers in literacy. Reading and comprehension assessment was conducted with the use of the Neale Analysis of Reading and analysed by means of a t‐test. Results show that the mean reading age of ex‐Reading Recovery children was nearly 12 months superior to that of the Comparison group and that the mean comprehension age was nearly 13 months superior at very highly significant levels. The results strongly suggest that Reading Recovery tuition at age 6 years enabled the 121 ex‐Reading Recovery children to make greater progress in literacy than children in the Comparison group.     

Democratic and Anti-Democratic Regulators of the Internet: A Framework

We employ Lessig's framework of regulation to conceptualize the relationship between the Internet and democracy. Lessig defines four classes of regulators, forces that control and define systems such as the Internet. They are markets, architectures, norms, and laws. We propose that a “democratic regulator” is a force that serves to enhance civil or political liberties. And we argue by example that there are democratic (and, indeed, anti-democratic) regulators that control aspects of cyberspace. Expressing the democratic effects of the Internet in this manner may prove useful for future comparisons across existing Internet and democracy theories, especially in the realm of quantitative analyses.     

Interpretative Responses to English Educational Television

The paper is concerned with the need to stimulate and evaluate pupils’ responses to educational television broadcasts in English. In particular, it presents a comparative assessment of written follow‐up work during a series of broadcasts. Case study methods are used within one comprehensive school and involve 49 15‐year‐old pupils. Results suggest that those pupils consistently engaging in small‐group discussion are likely to produce better written work and to develop greater independence in formulating their ideas.