Role of Homocysteine in Cognitive Impairement and Alzheimer’s Disease

A high circulating concentration of the non proteinogenic amino acid homocysteine has been implicated as a risk factor for Alzheimer’s Disease and its prodromal stage, mild cognitive impairement. Furthermore, hyperhomocysteinaemia has been directly attributed to a deficiency in vitamins B12, folate, and B6. Several studies have demonstrated decrease in progression of mild cognitive impairement to Alzheimer’s Disease, and some have even shown an improvement in cognition after vitamin supplements with B12 and folate. Plausible mechanisms linking hyperhomocysteinaemia to Alzheimer’s and cognitive impairement have been hypothesized and demonstrated in hyperhomocysteinemic mice models. However, some studies have not elucidated any benefit of vitamin supplements in subjects with cognitive impairment. Hence, multicentric clinical studies need to be conducted to substantiate the mechanisms of neuronal degeneration due to hyperhomocysteinaemia and to demonstrate the beneficial effect of folate, B6 and B12 supplements on cognition.     

跨世纪我国学校体育发展战略与对策研究

在全国范围对我国中小学体育工作现状作大样本调查,基本上摸清有关体育教学、课余体育训练、体育师资队伍和体育经费、场馆建设的状况,并进行因素分析。在现状分析基础上,确定５类１２项具体目标,经科学预测,提出在本世纪末学校体育发展战略目标以及实施目标的基本对策。     

一种基于Flash技术的CPU仿真实验解决方案

给出了CPU仿真实验中的一些基本概念,介绍了Flash技术以及提出了该技术在教学领域中应用的优势和必然性,并采用面向对象的编程思想(OBB)。利用Action Script解决了元件类层次及其显示问题、系统的交互问题、信号同步及动画显示的问题。最后,通过各系统的协同设计实现了CPU的仿真实验。     

Curriculum Interventions for Area Measurement Instruction to Enhance Children’s Conceptual Understanding

This study examined the effectiveness of 3 curriculum interventions focused on strengthening children’s ability to solve area measurement problems and explored the instructional perspectives of the instructor who implemented the interventions. The interventions involved various degrees of emphasis on area measurement and knowledge of 2-dimensional geometry. Participants were 131 fourth graders, recruited from a city in northern Taiwan, and 1 instructor. The results confirmed the effectiveness of an enriched curriculum integrating knowledge of 2-dimensional geometry in enhancing children’s conceptual understanding of area measurement. The group that received the enriched curriculum outperformed the other groups that received the curricula stressing only 2-dimensional geometry or numerical calculations for area measurement in solving the area problems requiring mathematical judgments and explanations. The curriculum also facilitated children’s reasoning in distinguishing between the perimeter and area of a rectangle, which required higher-order mathematical thinking. Interview data revealed that approximately all children from the 3 intervention groups could identify the mathematical subject-matter components highlighted in the curricula. Interviewees tended to consider the use of formulae to solve area measurement problems to be important, despite some differences in learning gains among the 3 groups. In interviews, the participating instructor revealed a change of perspective regarding the importance of offering students opportunities for manipulation and geometric operations when teaching area measurement, prompted by curriculum enactment.     

Gödel’s proof

In 1931, the great Austrian mathematician Kurt Gödel proved “all consistent axiomatic formulations of number theory include undecidable propositions”. This discovery of Gödel and its proof had enormous repercussions in mathematics and computer science. The proof hinged upon the writing of a self-referential mathematical statement, in the same way as the liar’s paradox — I am lying — is a self-referential statement. In this three-part article, we describe Gödel’s discovery and his famous proof.