DNA genotyping of unbuffered formalin fixed paraffin embedded tissues

Formalin-induced DNA degradation was studied at different fixation times (3, 7, 16 and 32 days) each on 10 formalin fixed paraffin embedded tissues (FFPET) stored for 15 years at room temperature.The four different extraction protocols used in this study showed that Chelex100 extracts performed the best at 3 and 7 days of formalin fixation (DFF) (with regard to the quantity and the quality of the DNA). However, Qiamp extracts showed better results for long sized alleles, as well for single polymerase chain reaction (PCR) amplifications after 16 and 32 DFF, as for multiplex PCR at shorter fixation times. DNA degradation is expressed by the size of the amplified alleles, only 100 bp templates surviving after 32 DFF (AMG locus). Single locus amplifications (CD4 and FES/FPS alleles) performed better than multiplex PCR (ProfilerPlus), with nearly 100% positive results at 7 DFF. In both types of amplifications, the success rate decreased proportionally with the time of formalin fixation and, consequently, with the size of the required DNA template.     

Real-time PCR designs to estimate nuclear and mitochondrial DNA copy number in forensic and ancient DNA studies

We explore different designs to estimate both nuclear and mitochondrial human DNA (mtDNA) content based on the detection of the 5' nuclease activity of the Taq DNA polymerase using fluorogenic probes and a real-time quantitative PCR detection system. Human mtDNA quantification was accomplished by monitoring the real-time progress of the PCR-amplification of two different fragment sizes (113 and 287 bp) within the hypervariable region I (HV1) of the mtDNA control region, using two fluorogenic probes to specifically determine the mtDNA copy of each fragment size category. This mtDNA real-time PCR design has been used to assess the mtDNA preservation (copy number and degradation state) of DNA samples retrieved from 500 to 1500 years old human remains that showed low copy number and highly degraded mtDNA. The quantification of nuclear DNA was achieved by real-time PCR of a segment of the X-Y homologous amelogenin (AMG) gene that allowed the simultaneous estimation of a Y-specific fragment (AMGY: 112 bp) and a X-specific fragment (AMGX: 106 bp) making possible not only haploid or diploid DNA quantitation but also sex determination. The AMG real-time PCR design has been used to quantify a set of 57 DNA samples from 4-5 years old forensic bone remains with improved sensitivity compared with the slot-blot hybridization method. The potential utility of this technology to improve the quality of some PCR-based forensic and ancient DNA studies (microsatellite typing and mtDNA sequencing) is discussed.     

Underpinning success in the real world of corporations law

This paper reports on an action research project which sought to evaluate and guide ongoing teaching and learning development in Principles of Corporations Law, a semester-long unit of study. Typically, enrolments in this subject area include students from a range of cultural contexts for whom the legislative and administrative concepts of the unit are unfamiliar and who also experience significant difficulties with cultural conventions of communication and business practice. At our university, unit enrolments include a high proportion of distance education as well as non-English speaking background (NESB) students, predominantly from China, who have not studied units formerly considered as prerequisite, and many of whom experience difficulties with basic academic skills. As the development team planned and created teaching features to ensure better learning outcomes for these students, it was clear that some truly contextual thinking as well as some practicable solutions would be required. While we had determined in the redesign planning that scenario- or problem-based learning (PBL) with its emphasis on finding, understanding and using information in context, was best suited to help students acquire the skills that underpin success in the unit, our experience in the project indicated students had a broader range of more basic needs. It emerged that students were struggling with fundamental issues that would need to be addressed before real change could occur.     

国家自然科学基金资助项目形成的知识产权归属问题研究

与私人投资相比 ,国家自然科学基金在资助的目的、资助的领域和投入的对象方面均有所差异。当前美国等发达国家和地区的立法对国家计划项目的成果归属所采取的放权原则值得我国借鉴。我国在确定国家自然科学基金资助项目形成的知识产权归属时应以适度放权为原则 ,以激励创新和促进利益平衡。