Polymorphisms in genes involved in folate metabolism as maternal risk factors for Down syndrome in China

Objective: To explore the relationship between genetic polymorphisms in methylenetetrahydrofolate reductase (MTHFR), methionine synthase reductase (MTRR), the central enzymes in folate metabolism that affects DNA methylation and synthesis, and the risk of Down syndrome in China. Methods: Genomic DNA was isolated from the peripheral lymphocytes of 64 mothers of children with Down syndrome and 70 age matched control subjects. Polymerase chain reaction and restriction fragment length polymorphism were used to examine the polymorphisms of MTHFR 677C→T, MTRR 66A→G and the relationship between these genotypes and the risk of Down syndrome was analyzed. Results: The results show that the MTHFR 677C→T polymorphism is more prevalent among mothers of children with Down syndrome than among control mothers, with an odds ratio of 3.78 (95% confidence interval (CI), 1.78～8.47). In addition, the homozygous MTRR 66A→G polymorphism was independently associated with a 5.2-fold increase in estimated risk (95% CI, 1.90～14.22). The combined presence of both polymorphisms was associated with a greater risk of Down syndrome than the presence of either alone, with an odds ratio of 6.0 (95% CI, 2.058～17.496).The two polymorphisms appear to act without a multiplicative interaction. Conclusion: MTHFR and MTRR gene mutation alleles are related to Down syndrome, and CT, TT and GG gene mutation types increase the risk of Down syndrome.     

《躺在黑暗中》的艺术手法

《躺在黑暗中》是斯泰伦的成名作。小说通过主人公悲惨而短暂的人生记录了社会、情感和精神等方面混乱无序的状况。作者使用了多视角叙述、内心独白和并置平行等创作手法深刻地透视了小说人物,特别是悲剧主人公在面临传统道德沦丧、宗教信仰危机时,所经历的内心冲突和痛苦挣扎。     

唐氏综合症儿童语言发展研究的现状分析

从前语言阶段、语音和词汇发展、形态句法习得和语用发展这四个方面对以英语为母语的唐氏儿童语言发展研究的现状和成果作了分析,并在此基础上提出今后的研究趋势以及在我国开展唐氏综合症儿童语言发展研究的意义和紧迫性。     

Can individuals with Down syndrome acquire alphabetic literacy skills in the absence of phoneme awareness?

Two studies investigating the relationship betweenphoneme awareness and word reading ability in Downsyndrome (DS) are reported. The first study included33 Brazilian individuals with DS (mean age = 23years). They all had begun to read and all showedclear signs of phonological recoding skills. Thirty-three normal children (mean age = 7 years),matched with the individuals with DS for readingability, participated as controls. The second studyincluded individuals with DS with a wider range ofreading ability: a group of 46 readers (mean age = 22years) and a group of 47 nonreaders (mean age = 18years). The results question Cossu, Rossini, andMarshall's (1993a) claim that phoneme awareness is notrelated to alphabetic reading acquisition in DS.Although the individuals with DS who participated inthe first study performed rather poorly on a task thatpresupposes the ability to explicitly manipulatephonological representations, they performed quitewell on a task assessing the ability to detectphonemic similarities in words. We suggest that it wasthis ability that enabled them to acquire phonologicalrecoding skills as well as they did, despite theircognitive limitations. The results of the second studywere consistent with this interpretation. The abilityto detect phonemic similarities in wordssignificantly differentiated between the readers andthe nonreaders, even after we controlled forvariations in letter knowledge, intelligence, andchronological age.     

利用Top—Down Design模块进行工装设计

简述利用Pro／Engineer中Top—Down Design小型模块,进行组件设计以及在小型工装设计中的应用体会。     

生态批评视角下的《去吧,摩西》

生态文学批评是当代文学研究最重要的任务之一。《去吧,摩西》中的艾萨克在法泽西、老熊和大森林的影响和熏陶下成长,长大后自愿放弃罪恶的家产,自食其力地过着简朴的生活,这体现了作者尊重自然和保护环境的思想。同时,福克纳对于人类目光短浅、贪图眼前的蝇头小利导致森林惨遭砍伐,从而造成生态环境遭到严重破坏的行为感到无奈。事实上,自然不依存于人类,人类却始终依存于自然,作为自然的一个组成部分,人应当与自然和谐相处。     

例谈运用行为矫正法改变智力障碍儿童之不良行为

在特殊教育领域,行为矫正法正在越来越广泛地被应用。本文从改变智力障碍儿童的不良行为入手,通过具体的案例分析,对运用行为矫正法提高智力障碍儿童的生活自理能力、社会适应能力进行实践总结和反思,以期对行为矫正法在特殊教育领域的应用有所指导。     

The Concept of Tens and Hundreds in Students with Down Syndrome

ABSTRACT

We present an evaluation of the understanding that adolescents and adults with Down syndrome (DS) have of the decimal number system. The results of two studies are presented. The first was a case study with interviews of three adolescents and three adults with Down syndrome. Our results indicate that their conceptual understanding of the meaning of the tens and hundreds places is not as well developed as their ability to read, write and work with numbers of up to three digits. We also analyse the progress made by a 17- year-old student with Down syndrome after following a learning programme intended to improve her understanding of the tens place. To this end, we designed number tasks using four constructs: counting, grouping, partitioning and ordering. The student’s achievements in the counting construct were greater than in the others, exhibiting an understanding and use of the tens as a unit of counting to solve many of the number tasks proposed. Also evident was a progression in her understanding of the positional value. We observed differences in her success rate and variability in her responses depending on the method used in the tasks to represent the numbers.     

The efficacy of `whole word' versus `analytic' reading instruction for children with Down syndrome

An intervention study was conducted toinvestigate whether children with Down syndrome(DS) would benefit from an `analytic' approachto reading instruction, which encompassedexplicit training in phonological awareness.Participants were seven English-speakingchildren with DS aged 8;6 (years;months) to11;1, who demonstrated little or nononword-reading ability prior to intervention.The children received weekly instruction (forsix weeks) in reading aloud 30 regularly speltmonosyllables (e.g., ten, bake) using an`analytic' approach, in which words werelearned by combining onsets with rimes (fourchildren), or a `whole-word' approach (threechildren). Participants' oral reading wasassessed pre- and post-intervention using areading test comprising the 30 trained wordsand 30 untrained (generalisation) words. Mostchildren (six out of seven) read more trainingwords correctly after intervention than before,with significant improvement shown by fourchildren (two trained analytically, and twotrained with whole words). More importantly,reading of generalisation words improvedsignificantly in only three children, all ofwhom had received analytic training. It wasconcluded that children with DS benefit from ananalytic approach to reading instruction, eventhough their auditory-verbal memory (assessedusing digit span) is poor.     

Children's attitudes toward their peers with Down Syndrome in schools in rural Ireland: an exploratory study

Increasingly, children with Down Syndrome are attending mainstream schools, but evidence suggests that these children are more prone to peer rejection and other problems when compared with their non‐disabled counterparts. However, relatively little is known about children's attitudes toward their peers with moderate to serious learning disabilities, including Down Syndrome. This study assessed the attitudes of non‐disabled primary school children (n = 118) in mainstream education toward their peers with Down Syndrome. A secondary aim was to assess whether exposure to audiovisual material promoting inclusion had any immediate effects on overall attitudes. A cross‐sectional, questionnaire‐based survey was administered in four rural‐based schools. The results showed that female participants over 10 were the most sociable. Overall attitudes toward inclusion were consistently and statistically significantly more negative than those toward sociability. Other factors, such as contact with peers with Down Syndrome, were not related to attitudes. Neither was there any change in overall attitudes following exposure to the promotional material. Further work is needed to identify factors underpinning the attitudes of non‐disabled children to their peers with Down Syndrome and how best to promote inclusion in mainstream schools.