工科线性代数的教学策略研究

线性代数相对与其他课程具有体系感、较强的逻辑性和抽象性、应用非常广和计算量非常大的特点。而当前线性代数教学面临的形势是:任课老师教学工作量大和学生自觉性不高,工科学生学习数学的兴趣比学专业课的兴趣低,工科学生的数学基础普遍降低,课时非常紧张,现在大学生做作业的主动积极性不高。因此,要调动学生的学习积极性,关键在于让学生对这门课感兴趣,要善于启发和引导学生的思维,充分利用多媒体课件,培养或是引导学生的兴趣,要善于引导学生对内容归纳和总结,学会融会贯通。     

中学生物教师继续教育相关问题的调查研究

职后继续教育的课程设置对教师素质有一定的影响,采用问卷调查、文献分析和访谈等方法,对中学生物教师继续教育所应开设的课程、教学形式等继续教育方面的问题进行研究,并提出相应建议。     

Recurrent de novo point mutations in lamin A cause Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder characterized by features reminiscent of marked premature ageing. Here, we present evidence of mutations in lamin A (LMNA) as the cause of this disorder. The HGPS gene was initially localized to chromosome 1q by observing two cases of uniparental isodisomy of 1q-the inheritance of both copies of this material from one parent-and one case with a 6-megabase paternal interstitial deletion. Sequencing of LMNA, located in this interval and previously implicated in several other heritable disorders, revealed that 18 out of 20 classical cases of HGPS harboured an identical de novo (that is, newly arisen and not inherited) single-base substitution, G608G(GGC > GGT), within exon 11. One additional case was identified with a different substitution within the same codon. Both of these mutations result in activation of a cryptic splice site within exon 11, resulting in production of a protein product that deletes 50 amino acids near the carboxy terminus. Immunofluorescence of HGPS fibroblasts with antibodies directed against lamin A revealed that many cells show visible abnormalities of the nuclear membrane. The discovery of the molecular basis of this disease may shed light on the general phenomenon of human ageing.